During the Cultural Revolution, when Song was a teenager, he performed manual labour as a sent-down youth in Sha County, Fujian.

In September 2014, he was elevated to executive deputy chief of the office, with the rank equivalent of a minister.

[1] In October 2015, Song accompanied Politburo Standing Committee member Liu Yunshan on a high-profile trip to North Korea.

In November 2015, he replaced Wang Jiarui as head of the International Department of the Chinese Communist Party.

[1] On 28 December 2022, he was appointed director of the Taiwan Affairs Office, succeeding Liu Jieyi.