In order to achieve precise multi-passes amplification on amplifiers and high pointing accuracy on target of laser beams, study on multiplexed beams automatic alignment of high efficiency excimer laser was described. Image-relaying structure with two cross-hairs, served as the near-field and the far-field references on the input beam and output beam, was proposed. In this way, the problems of nonexistence of nature alignment reference and parallel automatic alignment of multiplexed beams were solved accordingly. In the end, laser automatic alignment system of the three beams with double paths in pre-amplifier II was set up, which validated the feasibility of this method. Meanwhile, joint experiment of automatic alignment system including imaging system and feedback control structure was accomplished.