Abstract: Traditional optical methods which are used to measure the Smile effect of laser diode arrays(LDA) have problems such as high precision optical system setting up, high operator quality requirements, vast and complex subsequent data processing, long measuring time and so on. In this paper, a new method that scanned the N side of mounted LDA chips with the stylus of a mechanical contacting profiler was proposed to measure the Smile effect of LDA quickly. The measuring result was compared with the Smile effect measured by a traditional optical method. And the comparision indicates that their shapes are uniform and the difference is less than 1 micrometre. Using a profiler to measure the Smile effect of LDA takes little time less than 1 minute. The method can provide feedbacks quickly in chips bonding process to minimize the Smile effect, and can be easily integrated into high production lines to monitor the Smile effect of laser diode arrays in real time.