[Objective] The evolution and optimization mechanism of land use efficiency of counties (cities) in Zhejiang Province were analyzed in order to provide suggestions on realizing efficient and optimal allocation of land resources.[Methods] Using SBM-Undesirable model, entropy method, natural breakpoint method and geographical detector model, the evolution characteristics and optimization mechanism of land use efficiency of 69 counties (cities) in Zhejiang Province from 2007 to 2018 were studied.[Results] ① The evolution of land use efficiency of counties (cities) in Zhejiang Province was characterized by "three stages", and the difference between counties continued to narrow, showing a spatial differentiation trend of "high in the east and low in the west". According to the classification of land use efficiency of counties (cities) in 2018, Zhejiang Province could be divided into four zones:high efficiency, medium efficiency, medium efficiency and low efficiency. ② In 2007, 2012 and 2018, the importent driving factors of land use efficiency of counties (cities) in Zhejiang Province were the scale of capital investment, the regulation of resources and environment, and the ability of scientific and technological innovation. In 2018, the driving factors had different effects on land use efficiency of counties (cities) in different districts. ③ Based on the characteristics of land use efficiency of counties (cities) and their driving factors in 2018, this paper proposed land management and control policies for different districts and formulates differentiated land use optimization strategies based on the principle of "efficiency first".[Conclusion] The land use efficiency and its driving factors in Zhejiang Province have obvious temporal and spatial heterogeneity, and the ability of scientific and technological innovation is the primary driving factor at this stage.