With the advantages of “direct access” and “low-temperature process”, laser-assisted microprocessing can be used in the fabrication of OEICs to realize the optoelectronic compatibility. The achievements which our team has arrived at in the field of laser-assisted microprocessing are presented in this paper. Firstly, the experimental system has been improved, including the hardware platform's building and improving, and the software's designing, and finally developed into an automatic control system with the computer as the core and with optics, mechanism and electronics incorporated. Thus, the amount of experimental errors caused by human factors is decreased and the superior performance devices are accessible through laser assisted microprocessing. Meanwhile, a substantial theoretical analysis and experiments have been done on temperature, a key parameter of laser assisted microprocessing,which mainly includes the measurement of temperature, the analysis of the regularity for change of temperature and the study of the controlling of temperature. Consequently, the accuracy of laser-assisted microprocessing has been improved and the technology has been used for the planar InGaAs/InP PIN photodiode's fabricating.