Abstract: Laser wireless energy transmission system is a key part of space solar power station, its performance directly determines the feasibility of space solar power station technology, and accurate measurement of laser far-field spot distribution is an effective means to analyze and evaluate the performance of laser wireless energy transmission system.Aiming at the problems of solar power satellites with high orbit, long laser transmission distance, large receiving laser spot area, serious spot jitter due to atmospheric influence, and difficulty in spot energy distribution and spot shape measurement,a large area laser spot testing method based on optical energy detector array was put forward in this paper, which adopts spot distributed measurement and energy distribution reconstruction method to complete the far-field spot test of laser wireless power transmission system, which has the characteristics of distributed measurement and flexible layout. This method can realize the reconstruction of spot energy density distribution, the integral solution of received laser power, the calculation of beam divergence angle and other functions through inversion algorithm, and has strong adaptability, which provides an effective basis for the parameter revision of laser wireless energy transmission system load and the evaluation of on-orbit mission.