Scientific and technological talents are the key to achieving the strategy of building a strong country through science and technology. The identification, selection, training, use, reward, and flow of talents are all affected by policies, and the work of talents is highly dependent on policies. The degree of synergy of the science and technology talent policy affects the effect of the policy. The practical formulation and good implementation of policies for scientific and technological talents are the basis for the realization of policy objectives. Therefore, from the three aspects of policy objectives, policy formulation subjects and policy implementation subjects, according to the model of the synergy degree of the composite system, taking the 210 scientific and technological talent policies of nine cities in the Pearl River Delta in the Guangdong-Hong Kong-Macao Greater Bay Area as an example, it measures the orderliness of the subsystems of the scientific and technological talent policy and the degree of synergy in the composite system. The results show that since the establishment of the Guangdong-Hong Kong-Macao Greater Bay Area in 2017, the orderliness of the three subsystems has shown an overall increasing trend, the synergy of the composite system is at a relatively low level, and the synergy mechanism of the compound system of science and technology talent policy has not yet been formed. Finally, it puts forward relevant suggestions to promote the synergetic development of the scientific and technological talent policy compound system.