Lü Dai had been a commandery and county official, and fled south across the Yangtze to escape disorder. When Sun Quan took charge of affairs, Lü Dai went to his headquarters and was sent out as acting Assistant of Wu County; when Sun Quan personally reviewed the granaries and prisoners of the various counties, Lü Dai answered according to the law and pleased him greatly, so he was made Recorder (lushi), and then sent out as Chief of Yuyao, where he recruited more than a thousand hardy men. When the bandits Lü He and Qin Lang rose in rebellion in the five counties of Dongye in Kuaiji, he attacked them with Jiang Qin and others, captured both men and pacified the five counties. Records, Wu 15 §32
According to the biography of Wu Fan, when Wu Fan predicted in the jiawu year that Liu Bei would take Yi Province, Lü Dai, returning from Shu, had met Liu Bei at Baidi and came back saying that Liu Bei's followers had scattered and nearly half had died, so the venture would not succeed. Wu Fan said that what he spoke of was the Way of Heaven, while what Lü Dai had seen was the affairs of men, and in the end Liu Bei did take Shu. Records, Wu 18 §4
In the 20th year of Jian'an (215) he led ten generals, including Sun Mao, in the campaign to seize Changsha and the other two commanderies. When the officials of four counties including Ancheng entered the city of Yinshan to resist, he besieged them and received their surrender, and Sun Quan left him to guard Changsha. When Wu Dang, Chief of Ancheng, and the General of the Household Yuan Long rebelled again in league with Guan Yu, Lu Su attacked You County while Lü Dai attacked Liling, captured Yuan Long and beheaded him. He was promoted to Administrator of Luling. Records, Wu 15 §33–34
In the 1st year of Yankang (220) he replaced Bu Zhi as Inspector of Jiao Province. When Qian Bo, a bandit chief of Gaoliang, asked to surrender, Lü Dai, exercising his authority to act on the emperor's behalf, made him Commandant of the Western Division of Gaoliang; he also crushed the barbarian bandits of Yulin, and captured Wang Jin, who had raised a rebellion on the borders of Nanhai, and sent him to the capital. Those beheaded or captured numbered more than ten thousand. He became General Who Pacifies the South, was granted the Credential, and was enfeoffed as Marquis of a Chief District (duxiang hou). Records, Wu 15 §35
When Shi Xie, Administrator of Jiaozhi, died, Sun Quan made his son Shi Hui Administrator of Jiuzhen and sent Chen Shi to be Administrator of Jiaozhi. Lü Dai divided the province, making the three commanderies south of the sea Jiao Province and the four commanderies east of the sea Guang Province, and himself became Inspector of Guang Province. When Shi Hui refused to obey and held Haikou to block the new inspector Dai Liang, Lü Dai asked to punish him and crossed the sea day and night with three thousand troops. When someone said that Shi Hui, with the goodwill of generations behind him, had the whole province's support and should not be taken lightly, Lü Dai replied that if they fell upon him while he was unprepared they would surely defeat him, but if they hesitated the tribes of the seven commanderies would rise in response like gathering clouds. Records, Wu 15 §36–37
Shi Hui was greatly alarmed and came out bare-shouldered with his six brothers to welcome Lü Dai. According to Shi Xie's biography, Lü Dai first sent Shi Kuang, an old acquaintance, to reassure them that they would come to no harm if they admitted their guilt, and had those who came out to meet him put their clothes back on; then the next day, inside his tent, he read out an edict charging them with their crimes, beheaded them all and sent their heads to Wuchang. When Shi Hui's senior officers attacked, he crushed them and became Marquis of Panyu, and he abolished Guang Province and merged it back into Jiao Province. He campaigned against Jiuzhen and sent attendant officers to spread the influence of the state, whereupon the kings of Funan, Linyi and Tangming sent tribute, and he became General Who Guards the South. Records, Wu 15 §38Records, Wu 4 §47–48
In the 3rd year of Huanglong (231) he was recalled to Oukou in Changsha and pacified the Man tribes of Wuling together with Pan Jun. In the 3rd year of Jiahe (234) he took command of Pan Zhang's troops and was stationed at Lukou, and the next year, when bandits in Luling, Dongye and Nanhai rose all at once, he directed Tang Zi and others to suppress them. In an edict Sun Quan said that Li Huan and Luo Li had evaded capture for years, and who could have beheaded them but for his strategy? After Pan Jun died, Lü Dai took charge of the documents of Jing Province and was at Wuchang together with Lu Xun, and when Liao Shi rebelled, he submitted a memorial and set out at once on his own initiative; he was appointed Governor of Jiao Province and crushed the rebels within a year. Records, Wu 15 §39–41
By this time he was already eighty, but he was hale and diligent and handled state affairs in person. In a letter, Zhang Cheng likened Lü Dai and Lu Xun to Dan, Duke of Zhou, and Shi, Duke of Shao, who had assisted the Zhou, and said that since Lü Dai leapt onto his horse without using a mounting step, he surpassed Lian Po. Records, Wu 15 §42–43
When Lu Xun died and Zhuge Ke replaced him, Sun Quan divided Wuchang into two divisions and gave Lü Dai the Right Division, and Lü Dai became Senior General-in-Chief. When Sun Liang took the throne, he became Grand Marshal. While he was in Jiao Province he sent no provisions home for years and his wife and children went hungry; when Sun Quan heard of this he rebuked his ministers and granted money, rice, cloth and silk every year. Lü Dai also recommended Xu Yuan, who was given to frank speech, valued his remonstrances, and when Xu Yuan died, wept bitterly, saying he no longer had anyone from whom to hear of his faults. Records, Wu 15 §44–46
He died in the 1st year of Taiping (256) at the age of ninety-six, and his son Lü Kai succeeded him. Lü Kai carried out all of his dying instructions to lay him in a plain white coffin, dress him in a coarse kerchief and a simple cloth robe, and bury him frugally. In his assessment, Chen Shou said that since the Shanyue frequently rebelled, Sun Quan had no time to defend against enemies abroad, and these ministers all put down the disorders within; Lü Dai, he wrote, was incorruptible, scrupulous and devoted to public duty. Records, Wu 15 §47 · 86