Qian personally chose Song to co-author the revised edition of his Engineering Cybernetics, regarded as a bible of Chinese military science.

[9] At the beginning of the Cultural Revolution, Song's home was ransacked by the Red Guards before Premier Zhou Enlai included him in the list of the top 50 scientists considered indispensable to national defence and afforded special protection.

[10] In the late 1970s, Song applied his expertise in cybernetics to the problem of population control and became a proponent of China's so-called one-child policy.

He was appointed deputy chief designer of JL-1, China's submarine-launched ballistic missile in February 1980 (under Huang Weilu), and Vice Minister of Aerospace Industry in 1982.

Thereafter, China's new leader Deng Xiaoping continued this program, reducing military spending and urging scientists to focus their energy on solving the country's urgent economic problems, including widespread poverty.

[11] Based on assumptions of future trends, Song and his group performed calculations that determined the "ideal" population for China in the next 100 years was 650 to 700 million, about two-thirds of its then-population of 1 billion.

[14] Following the Chinese central government's decision to advocate for one-child families in 1979, Song and his associates entered the picture, actively supporting and promoting the one child ideal through conference discussions in 1980 in Chengdu.

[17] Although some leaders, including Zhao Ziyang and Hu Yaobang, expressed doubts about its feasibility, at a top-secret high-level meeting convened in April 1980 Song won over many policymakers to his recommendation of universal one-child limits.

[19] Although it is widely agreed that Song's population projections influenced the speed and scope of implementation of one-child limits, several leading scholars have refuted Greenhalgh's thesis that Song "hijacked the population policymaking process" [20] and that he should be considered both the inventor and central architect of the one-child policy, a thesis that has often been regurgitated without much critical reflection.

[4] Wang et al. agree, concluding that "the idea of the one-child policy came from leaders within the Party, not from scientists who offered evidence to support it.".