 The son of a shepherd and cattle farmer, he became a clerk in local and provincial administrations at age 16.Following the Mongolian Revolution of 1921, he joined the Mongolian People's Party (MPP) and secured an important position in the Ministry of Finance in 1922.Aligning himself with the leftist faction of the party early on, Sambuu supported the purges and executions of both Dogsomyn Bodoo in 1922 and party leader Soliin Danzan in 1924.