This study designs and develops a set of far-field laser spot energy testing system based on energy density detecting array. Through installing energy density detectors on the characteristic location of energy density target, the practical value of laser’s energy could be adopted. Meanwhile, by the use of visible light image equipment, the energy density distribution image of laser spot with a wavelength of 532nm on target surface could be obtained. After that, the energy density of each spot on the target surface as well as the energy density distribution have been figured out by fusing the grey level of laser spot image with the practical energy value detected by laser energy probes. The result shows that this system, which is simple, reliable, and available for the far-field laser energy density measurement under all circumstances, is capable of precisely measuring the far-field laser energy distribution with more than 1km with few measurement errors.