Catastrophe Optical Damage (COD) usually occurs at the front cavity surface of quantum well semiconductor laser diodes, and it is a great trouble to its output power and life. The preparation of Non-Absorption Window (NAW) by quantum well intermixing based on Impurity Induced Disordering (IID) is a common method for inhibiting COD at the cavity surface, which has a great potential to achieve blue shift with high efficiency and low cost. In this paper, Si impurities were used to induce quantum well intermixing. The epitaxial structure of the InGaAs/AlGaAs quantum well semiconductor laser diode and the Si impurity diffusion layer and Si3N4 protective layer were grown by a Metal Organic Chemical Vapor Deposition (MOCVD) device. After several thermal annealing treatments, the Si impurity diffusion inducing the mutual diffusion between the quantum well and the barrier, which widened the band gap of the quantum well area and resulted in blue shift of the output wavelength, reducing the absorption of the emitted light. Usually thermal annealing will affect the surface morphology of epitaxial surface, and the surface morphology may affect the preparation of electrode in the subsequent packaging process. Combined with an optical microscope and photoluminescence (PL) spectrum, experimental results indicate that about 93nm wavelength blue shift can be observed under the annealing condition of 825℃/2 h. In conclusion, annealing can affect the topography of the epitaxial wafer's surface, but it does not affect the blue shift of wavelength and the preparation of electrode.