Accelerating the development of e-government and optimizing government services are new tools to promote government innovation. Based on the quasi-natural experiment that county-level government affairs disclosure and government service pilot, this paper constructs a spatial double-difference model (SDID) to investigate the direct effect and spillover effect of e-government on the efficiency of "local-neighbor" government governance. Furthermore, this paper explains the internal mechanism from the dual dimensions of control, accountability and service improvement. The results show that the e-government can significantly improve the efficiency of "local-neighbor" government governance. The effect of e-government on governance efficiency has typical heterogeneity in the dimension of institutional environment, administrative hierarchy and geographical division. Government affairs disclosure, interactive response and online services are the key paths for e-government to improve the efficiency of ocal governance. The peer effect of inter-regional e-government development is an important spillover mechanism for the simultaneous improvement of the governance efficiency of neighboring governments. The research conclusions of this paper are helpful to deeply understand the influence mechanism of e-government on my country's government governance efficiency, and provide policy suggestions for the improvement of governance efficiency.