Abstract: A comprehensive review of the historical process of the continuous increase in the level of the overall level of basic pension insurance for urban employee is conducive to the realization of national integration in the true sense. By sorting out the changing process of the continuous increase of the integration level of basic pension insurance for urban employee, it summarizes that the changing process of the integration level is characterized by a combination of induced and forced institutional changes, and the trajectory of change exhibits a gradual and forced stepped pattern. Based on summarizing the changing characteristics, the diffusion process of the integration level of basic pension insurance for urban employee is empirically analyzed specifically using the event history analysis method by taking the provincial unified revenue and expenditure policy as an example. It is found that, firstly, the fact that governors originate from a different region has a significant negative effect on the adoption and innovation of the provincial unified revenue and expenditure of basic pension insurance for urban employee. And an explanation has been provided from the perspective of policy attributes. Secondly, intra-regional factors play an inducing role in the process of upgrading the level of basic pension insurance for urban employee. The proportion of neighboring provinces adopting the provincial unified revenue and expenditure policy for basic pension insurance for urban employee and the release of the central government's signal will significantly accelerate the process of implementation of the provincial unified revenue and expenditure policy. This proves empirically that the process of change in the level of basic pension insurance for urban employee is characterized by forced institutional change together with induced institutional change. Based on the diffusion mechanism of the provincial unified revenue and expenditure policy of basic pension insurance for urban employee, it proposes that the national unification can promote the implementation of the national integration policy by taking into full consideration the internal characteristics of the region and by stimulating the endogenous motivation of local officials.