When the German attack on the Soviet Union began on 22 June 1941, his 28th Rifle Corps was deployed to the 4th Army on the Western Front and was forced to withdraw from the Brest region towards Kobryn and Bobruisk.

During these hostilities, Popov was seriously injured and, after his recovery in September 1941, was appointed deputy commander of the logistics department of the 50th Army.

In the summer of 1943, his army took part in the Smolensk Operation, in which the German defense at Kirov was broken and the advance towards Roslawl, Snigirjowka and Tschaussy took place.

During the East Prussian Offensive, the army advancing from the Serok bridgehead broke through the enemy's defense and then liberated the city of Modlin.

After crossing the Oder, the German Stettin Group was defeated and then it reached the city of Rostock and the coast of the Baltic Sea near Wismar by 3 May.

In June 1955 he was appointed head of the Military History Faculty for the training of army officers and in January 1958 on the general staff for research work.