COMSOL software is used to simulate the steady-state output of volume Bragg grating (VBG) ex ternal cavity semiconductor laser,and the influence of VBG on the temperature characteristics of semiconductor laser is studied.Two kinds of VBG (15% and 20%) are used to lock the mode of 888 nm semiconductor laser in external cavity.The output characterist ics and temperature characteristics of semiconductor lasers under the condition of external cavity m ode locking are tested and analyzed.The results show that the VBG external cavity structure can improve the spectral cha racteristics of the semiconductor laser and increase the operating temperature of the semiconductor laser.When the VBG with 15% diffraction efficiency is used for external cavity mode locking,th e maximum output power is 10.7 W,the output wavelength is stable at 888 nm,and the spectral linew idth is 0.3 nm at 25 ℃.