Abstract: In recent years, major breakthroughs have been made in deep oil and gas exploration in the North-central Xihu Depression, which confirms the prospect of deep reservoir exploration. However, the heterogeneity and complexity of deep reservoir are the main problems in exploration. The key to improve the success rate of exploration is to determine the main controlling factors of high-quality reservoir development. On the basis of the existing research results, through a large number of laboratory analysis data such as rock flakes, scanning electron microscopy and X-ray diffraction, this paper focuses on analyzing the controlling factors of chlorite development, the different sub-genesis, action efficiency and range of chlorite in the study area. The reaction mechanism of diagenesis of chlorite film-residual intergranular pores, which plays a key role in the development of deep high-quality reservoir in the study area is discussed. It is believed that authigenic chlorite film plays a constructive role in the diagenesis of deep sandstone reservoir, and promotes the preservation of deep sandstone reservoir pores by inhibiting the siliceous cementation and pressure dissolution of clastic rock. Through the research, the conditions for the development of high-quality reservoirs in the deep layer of the study area are defined, which is of reference significance for the oil and gas exploration in this area.