In order to minimize the effect of microlens array position error on homogenized spot, the influence of microlens array relative position error on diode laser beam's homogenized spot is researched, and a laser diode beam homogenization system based on microlens array is designed. The position errors owning to the variation of six degrees of freedom between the two arrays are classified into distance error, offset error and rotation error, and the effects of the three kinds of position errors on beam homogenization are studied. The homogenization system is tested by a laser diode array consisting of 6 bars, a uniform pumped spot with 90.75% homogeneity is achieved, and the factors influencing the spot homogeneity are analyzed. ©, 2015, Editorial Office of High Power Laser and Particle Beams. All right reserved.