1March, 932, Hu Jin joined China * * * and served as the company commander of the machine gun. 1August, 933, he was promoted to deputy battalion commander of No.1 battalion. During this period, Hu Jin participated in many important battles in Shuikou, Guangdong, Guangchang, Jiangxi and Jianning, Fujian, and bravely completed the tasks assigned to him by his superiors. Especially in the Shuikou campaign in Guangdong, the task given by the superior to Jinhu's machine gun company was to cover the main force and prevent the enemy from escaping. At that time, Hu Jin organized fire to kill four or five hundred enemies, and the other two tried to escape. Hu Jin led an infantry platoon to rush up, captured more than 40 enemies alive, seized 3 light machine guns, 2 heavy machine guns and more than 40 rifles, successfully completed the task and was praised by the division. In the battle of Guangchang, Jiangxi, the task of Jinhuying was to cover the transfer of the main force. They persisted for two days and one night, and the enemy's heavy troops surrounded them inside and outside, which was full of dangers. At this important moment, Hu Jin took the lead, brandishing mauser pistol in one hand and saber in the other, and led the whole battalion to run from left to right, finally fighting his way out of the enemy's encirclement. In this battle, Hu Jin was seriously injured. He was shot five times in a row by the enemy and his right leg was injured by a bomb.

1934 10, the fifth counter-campaign failed, and the Central Red Army withdrew from Jiangxi and began the Long March. Also participated in the battle of the transition river. After a long journey and marching, Hu Jin's wound recurred and it was very difficult to walk. Soldiers used stretchers to carry him over the snow-capped mountains, out of the grasslands, and arrived in northern Shaanxi smoothly.

In northern Shaanxi, he was transferred to the second regiment of the 28 th Army as the deputy head. At this time, the main force of the Red Army crossed the Yellow River eastward, but Hu Zongnan troops made trouble in the rear. The superior ordered their second regiment to resolutely win Dingbian and Yanchi counties. After hard fighting, they smashed Hu Zongnan's attack and completed the task of covering the main force crossing the Yellow River eastward.

1August, 937, Hu Jin went to the Anti-Japanese Military and Political University to study. 1938 stayed in school after the expiration of the study period in March, and served as the captain of the fourth squadron of the fifth brigade of the Anti-Japanese Military and Political University. Later, he was appointed as the captain and general director of the Anti-Japanese University. 1August, 939, he was transferred to the head of the ninth regiment of the third column of Shanxi Youth Anti-Enemy. 1April, 940, transferred to the head of Yan 'an Security Corps. During this period, Hu Jin responded to the call of the CPC Central Committee, organized troops to defend Yan 'an, and led the troops to actively carry out mass production movements.

During the War of Liberation, Hu Jin successively served as deputy brigade commander of the 19th Brigade of the 7th Division of the Northeast Democratic Allied Forces, deputy commander of Suihua Military Division of Ximan Military Region, commander of the 2nd Division of the Northeast Democratic Allied Forces Cavalry Column, chief of staff of the War Logistics Command of the Logistics Department of the Northeast Field Army, and minister of the 4th Division of the Logistics Department of the Fourth Field Army. During this period, Hu Jin led the troops to complete the combat tasks assigned by their superiors many times and made positive contributions to the liberation of Northeast China. Especially in the battle to liberate Lin Dian and Fuyu counties, Hu Jin led all officers and men of Suihua Military Division of Ximan Military Region, annihilated more than 2,000 enemies guarding the city, and seized a large number of munitions. When attacking Qiqihar, it not only wiped out the enemy 1800, but also seized more than 50 cars and tanks 10, which was praised by the headquarters.

From 65438 to 0950, Hu Jin transferred to the navy, and served as vice president of naval artillery school, president of naval reserve school, president of Nanjing artillery school, and deputy director of naval ordnance department of the Chinese People's Liberation Army. Although he is in poor health, he still goes deep into the grassroots and grasps first-hand information to guide his work. In the Naval Preparatory School, he tried to encourage students to study for the revolution, and tried to become the pillar of the navy, and trained a number of cadres for the navy.

1964 after leaving his post, he still maintained the fine tradition of the army. 1988 was awarded the first-class Red Star Meritorious Medal by the Central Military Commission in August.