Yin returned to China in 1993 and started his career as a cadre of the Department of Education, Science, Culture and Health at the Research Office of the State Council. Later at the research office, he served as the head of its international department and as an inspection officer.[6]
From 2002 to 2003, Yin served as a visiting scholar at the Harvard School of Public Health. In May 2003, he began work at the Ministry of Health, where he served as deputy chief of staff, international cooperation director, chief of staff, and by September 2008, Vice Minister of Health. In 2004, he joined the executive committee of the World Health Organization.[6]
In February 2012, he was named head of the State Drug Administration. In April 2013, he was named deputy director of the newly created National Health and Family Planning Commission, and deputy director of the China Food and Drug Administration, which was the result of the amalgamation of several government departments.[6]
In March 2015, he started to serve as deputy party secretary of Sichuan Province; in May 2015, he also became provincial publicity chief.[7] It was notable that prior to 2015, Yin had no regional political experience at all.[8] On 29 January 2016, Yin assumed the post of Governor of Sichuan after his predecessor Wei Hong resigned in the wake of an internal party investigation into his conduct. Yin was the first provincial Governor to swear allegiance to the Constitution as part of his inauguration ceremony.[9]
On December 1, 2020, Yin was appointed as the party secretary of Fujian Province.[10] He served until November 13, 2022.[11]
Yin was an alternate member of the 18th Central Committee of the Chinese Communist Party and is a full member of the 19th Central Committee. He is a member of the 20th Politburo of the Chinese Communist Party.