Abstract: In experiment, three systems were designed to measure the energy distribution of the laser beam in the far field. Under the same conditions, the far field of the laser beam was measured independently by three instruments: long focus lens, rattle pair and multipleimage cameras. After compare and analyze the results, a new system was put forward in which a long focus lens with a pair of smallangle wedge was used. It only needs corresponding data processing for a focalspots line which was on the focal plane. The new system satisfied requirement for aberration and predigested image data processing.