Micro-lens array method is one of the widely utilized approaches to realize beam homogenization. This method can achieve large-area uniform spots in the focal plane by changing the focal power of the imaging lens. Herein, the feasibility of the scattering imaging method is analyzed theoretically and experimentally. In order to accurately measure the illuminance of spots in the focal plane, the mathematical relationship between the image gray scale value and the illuminance of spots in the target plane is established using the Zhang Zhengyou's camera calibration method, after considering the interfering factors such as the reflectivity of diffusing plate and the off-axial angle of the camera. Bidirectional reflectance distribution function of the diffusing plate is experimentally calibrated. The illuminance distributions of the homogenized spots in the focal plane and its vicinity are measured for the principal integral lenses with two focal lengths. Experimental results show that when the focal lengths of the integral lens are 300 mm and 500 mm respectively, the laser fluxes are roughly equal and the measured spot sizes are basically consistent with the theoretical values in the target plane. By comparing the variation coefficients of spot distributions in the defocus observation plane for these two cases, the optimal position to realize homogenized spot distribution is obtained.