During the Russian Civil War, he was drafted into the Red Army in Petrograd in August 1919 and appointed a company commander in the 10th Reserve Regiment of the Northwestern Front. He commanded a march battalion of the front from September 1920, and in December became a company commander in the 96th Rifle Regiment of the 32nd Brigade of the 11th Rifle Division. With the division, he fought in the suppression of the Kronstadt rebellion, receiving a silver watch for capturing a battery. From May 1921 he served as an assistant battalion commander of the divisional training regiment. Mikhaylov and his unit subsequently participated in the suppression of the East Karelian uprising between December 1921 and March 1922. For capturing the Volazminsky factory, he was awarded the Order of the Red Banner, in addition to the To the Valiant Soldier of the Karelian Front badge for participating in the operation.