Microlens array is one of the typical devices of micro optical components,which is widely used in beam shaping,precision measurement,optical imaging and other scenarios.In this paper,the working mechanism of the microlens array scanning imaging system is studied,and the light field diffraction effect and stray light crosstalk that affect the imaging effect,are analyzed with emphasis.The derivation and simulation of the diffraction effect of the microlens array scanning imaging system is completed,and the relationship between diffraction effect and the focal length and subunit aperture is revealed,which provides guidance for the practical application of the microlens array scanning imaging system,theoretical support for the beam control application of the microlens array,and a basis for modeling and design of the microlens array.