During the Russian Civil War, he started his service as a commander of a company and quickly rose to higher ranks.

He then commanded the 20th Rifle Division (February–March 1919) and the Ufa army group (March–April 1919) which took part in the smashing of Aleksandr Kolchak’s White forces in the Ural area.

Velikanov led the defense of Orenburg from April to June 1919, and commanded shock infantry troops within the 1st Cavalry Army in February 1920.

He suppressed the Azerbaijani uprising in Ganja (May 1920), and took part in the campaigns in Armenia (December 1920) and Georgia (February–March 1921).

He became a Bolshevik party member in 1924 and served as a deputy commander of the North Caucasus Military District from 1930 to 1933.