潘漢年以犀利的筆鋒在文壇上崛起，1925年加入中國共產黨後，在中共中央的指示下，串連起30年代的左翼文學運動。其中以左翼作家聯盟的成立最為重要，這的聯盟以魯迅為首，勾串起當時的左翼文學。1931年，顧順章的被捕「叛變」，潘漢年臨危受命，轉入隱蔽戰線，任情報科科長。投入地下工作後的潘漢年，帶有強烈的神祕色彩，期間更替周恩來闢謠，打破當時伍豪脫黨的傳言。1933年，潘漢年以中華蘇維埃共和國臨時中央政府及工農紅軍代表的身分，與當時十九路軍簽訂協定，爾後更奉命與何長工一起代表紅軍與陳濟棠談判並達成協議，為中共紅軍「長征」邁出有利的一步。遵義會議後，與陳雲奉命前往莫斯科報告遵義會議和「長征」的情形。潘漢年在莫斯科期間，與南京國民政府武官鄧文儀晤談，開啟了「第二次國共合作」的先聲。1936年2月，受中共駐共產國際代表團團長王明的指派，回國與南京當局談判，此一時期的潘漢年代表中共，多次與陳立夫、張?等人交涉，西安事變爆發後，更扮演居中協調的角色。1937年抗戰爆發後，便穿梭於上海、香港兩地，建立起嚴密的情報網，為中共蒐集許多相當珍貴的情報。1945年抗戰勝利後，便積極的從事統一戰線及隱蔽戰線的工作，爭取社會輿論對中共支持，幫中國共產黨日後建政創造良好的條件。 Pan Hannian was risen conspicuously by trenchant writing and has concatenated the Activities of Left-wing literature amount 30 years with the directive of the Chinese Communist Party (CCP) Central Committee since 1925 when he joined the Chinese Communist Party. Among to those activities, to establish the League of Left-Wing Writers was the most important thing and led by Lu Xun meanwhile, it conspired the Left-wing literature. In 1931, he turned to hidden front as a leader of intelligence because his life was in a danger due to the rebel, Gu Shunzhang, was under arrest. During he worked on behind the scenes and was full of strong mystery, he also refuted rumors about the defection of Wu Hao for Zhou Enlai. In 1933, he was ordered to represent the Red Army to negotiate and reach an agreement with Chen Jitang and took a big step beneficially for the Long March after he has signed an agreement with the 19th Route Army as the identity of Provisional Central Government of Chinese Soviet Republic and on behalf of the Red Army. The harbinger of the second KMT-CCP Cooperation turned on he had a meeting with Deng Wenyi who worked as a Military attache of Nationalist Government. He was designated by Wang Ming, the leader of the Communist International, to negotiated with the Administration of Nanjing, and in the meantime he negotiated with Chen Lifu and Zhang Chong repeatedly in February 1936. After the Xian Incident, he acted as a peacemaker even more. Following the War in 1937, he founded the rigorous network of intelligence through the Shanghai and HongKong and also collected lots of valuable intelligences for the CCP. After the victory anti-war in 1935, he became positive on the United Front and work for the hidden front and fought for public opinions which support the CCP. Otherwise, he also created nice conditions to help the CCP establishes another regime.