When he returned to North Korea, Kim Il Sung was uncomfortable with his reputation and unwillingness to submit to him, and he was always anxious and vigilant and saw him as a strong static from the beginning.

In November 1945, he went directly to Pyongyang Station to support the settlement of North Korean soldiers who returned home.

He became the 2nd secretary of the Workers' Party of Korea, but in 1946 Kim Il Sung demoted him to the artillery commander of the security officer training battalion.

On May 10, 1947, in the presence of Choi Yong-geon and other People's Liberation Army officers, Kim Mu Chong insisted, “In return for fighting the blood of Korean soldiers in the Manchurian War, Joseon must obtain Jiandao”.

However, while patrolling Manpo in Jagang Province, he encountered an injured soldier from Palo County who was close to Mu Chong.

He was purged after being referred to the People's Army's military trial for charges of disobedience to orders, disloyalty of the fighting organization, and illegal murder in the retreat.

When Kim Moo-jung was killed in 1952, the coastal wave he led was destroyed by the August 1956 sectarian case and the 1958 Choi Chang-ik purge.

However, Kim Il Sung highly praised the activity in the memoir "With the Century" by describing the fact that heartlessness played a large role in the independent movement in North Korea and the achievements of the Chinese Communist Party.