Considering low precision and efficiency of manual operation in the alignment process between aspheric lens and semiconductor laser, a system of automatic alignment was designed based on the technology of machine vision which configured with high-performance light source of CCS and high-resolution camera of Basler, high-precision images could be obtained in real time. First, the edge of aspheric lens and the semiconductor laser was fitted into two straight lines according to the algorithms of progressive probability Hough transform and iterative weighted least squares. Then, the angle between two lines were calculated and adjusted automatically, high precision alignment between aspheric lens and semiconductor laser was achieved finally. Completing the whole process within 0.5 s at the accuracy of sub-micron level, the packaging efficiency, the accuracy of the aspheric lens and the semiconductor laser were improved greatly by system. Based on high performance configuration and precise image processing algorithm, the vision alignment system has greatly improved in the traditional packaging technology, which will greatly promote the encapsulation efficiency and accuracy of semiconductor lasers in the future.