Fan Kuai was born in poverty and slaughtered dogs in his early years. He had a close relationship with Liu Bang and once hid in Mangdang Mountain (now northeast of Yongcheng, Henan Province) with Liu Bang. With Xiao He and together, * * * put on the ring of the qin dynasty. When Liu Bang became Pei Gong, he made Fan Kuai his adjutant. Following Liu Bang's campaign, he first attacked Hu Ling and Yu Fang, defeated the army of Surabaya County Governor and Chief in Fengxian County, and then pacified Peixian County. In the battle between Qidong and Sima Ling, he performed heroically, beheaded fifteen heads, repelled the enemy, and was named a national doctor. When resisting Zhang Han's army, Fan Kuai took the lead in boarding the city, beheaded 23 people and was made a doctor.

Since then, he often followed Liu Bang's expedition and made great achievements. Siege Yang,, broken Li You (son of Reese) army, * * * beheaded 16, was given a title. In the battle of besieging the viceroy of Dongjun County, he defeated the enemy, beheaded 14 people and captured 1 1 people, and was awarded the title of five viceroy. Later, he defeated Qin He defenders, Zhao Ben, Yang Xiong and other troops. He took the lead for many times, captured the beheading and made meritorious deeds, and was named Cheng Jun of Qing and Xi 'an. After doing more, the income will be sealed. When Fan Kuai attacked Wuguan and took the overlord, he led the army to slay a surname, with ten heads, captured 140 people, and fell by 2,900.

Liu Bang led the army to enter and seal off the customs, and claimed the title of king in Guanzhong according to Chu Huaiwang's agreement of "first deciding the king of Guanzhong", which aroused Xiang Yu's dissatisfaction. He also sent Dangyang people, Bu and others to fetch Hangu Pass. Xiang Yu was stationed in Xixi (now the west bank of Xingfeng, northeast of Lintong, Shaanxi) after entering the customs, trying to kill Liu Bangjun. As early as after Liu Bang entered Xianyang, Fan Kuai urged Liu Bang to return to military hegemony (southeast of Jin 'an) and not to covet Qin Gong's luxury.