Abstract: In femtosecond laser random scanning two-photon microscopic imaging system, using a broadband two-dimensional acousto-optic deflector scanning femtosecond laser can increase scanning angle to 74 mrad, increasing two-photon microscopic imaging range. But broadband two-dimensional sound and light deflector has large dispersion in large angle scan, resulting in serious distortion of imaging edge and spot diameter of 2.3 μm. In order to improve image quality, a new dispersion compensation method is designed. Kepler's telescope system based on diffraction lenses can compensate different dispersions of different scanning angles. After dispersion compensation, imaging edge of spot diameter is less than 1 μm, so that wide range of scanning imaging is obtained and dispersions of all scanning angle are well compensated. Spot diameter throughout entire field of view is less than 1 μm and more uniform fluorescence excitation and imaging are achieved.