Abstract: In order to optimize the quantum well laser at 1.31μm wavelength in long distance optical fiber communication systems, strain compensated quantum well in active region of AlGaInAs/InP material was studied. Based on strain compensation method and Kronig-Panna model theory, the band structure of quantum well was calculated. The active region was consisted of 1.12% compressive strain AlGaInAs well layer and 0.4% tensile strain AlGaInAs barrier layer. ALDS software was used to simulate the design of the device and analyze the threshold and the steady state. The results show that the laser has a low threshold current of 9mA and a high slope efficiency of 0.4W/A at 25℃room temperature. In the potential barrier layer, the appropriate strain opposite to the strain of the potential well layer can reduce the average strain in the growth process, ensure the well growth of active zone, improve the band structure of quantum well effectively, enhance the limit ability of carriers, reduce threshold current, increase saturation power and improve device performance.