In order to obtain more complete test data of quantum-dot external-cavity lase rs,the InAs/InP quantum-dot external-cavity lasers using digital micro-mirror device (DMD) are successfully built up and their spectrum characteristics and the tuning range are measured.We also measure its tuning range and the corresponding change in the mode based on DMD quantum external cavity la ser dots.The spectrum characteristics of InAs/InP quantum-dot external-cavity laser based o n the grating and the DMD are compared theoretically and experimentally,and the differences between th e reflection spectrum and angular dispersion are obtained.And a new method base d on DMD will be applied to the external-cavity quantum-dot lasers.