Han did well in school, and left in 1904 to study military science in Japan, where he entered the artillery department of the Imperial Japanese Army Academy.

Han recruited technicians from Japan, Germany and other countries, purchased equipment, and developed weapon manufacturing under strict management.

After the establishment of the Army Reorganization Office of the Three Eastern Provinces, Han and Jiang Dengxuan were made its deputy commanders under Sun Liechen.

Han personally led a dare-to-die corps of 3,000 men against a strongly fortified position held by Cao Ying, ripping off his shirt and fighting bare-chested.

His men took heavy casualties but were ultimately successful, turning the flank of the Zhili defensive lines and helping win control of Shanhai Pass.

[8] Later in the campaign, Han attempted to remove an artillery officer serving under Guo Songling, infuriating the latter commander and almost causing him to abandon the battle.

[10][2] In January 1926, Zhang Zuolin's erstwhile ally Feng Yuxiang and his Guominjun declared war on the Fengtian Clique.

[11] On December 1, 1926, Zhang Zuolin became the commander-in-chief of the administration he had installed to lead the Beiyang Government, and Han was promoted to General of the Army.

In August, Han Linchun began secret negotiations with He Chengjun (a former classmate from the Japanese Imperial Army Academy) sent by the KMT.