He joined the Korea Justice Corps, which focused on Senol, took military responsibility, reorganized the definition group into the military department, and was recommended as the commander. In 1919, he, on the recommendation of the Provisional Government of the Republic of Korea, took up the position of general commander of the Northern Military Administration Office Army (Bungnogunjeongseo in Korean). His first action was to install a military center in the mountains of Wangqing County, where he himself became an educator on military leadership. Training under him was strict, and the tasks given to most of the troops under his command was focused on acquiring weapons. In September 1920, 298 people graduated from the First Military Academy.