High output power and long-term reliability are the prerequisites for the wide application of high power semiconductor lasers, but the optical catastrophic damage (COD) caused by cavity surface degradation at high power density restricts the maximum output power and reliability of semiconductor lasers. In order to improve the COD threshold of 915 nm InGaAsP/GaAsP semiconductor lasers, the primary wafer is epitaxially grown by metal organic chemical vapor deposition equipment. The influence of quantum well intermixing on the luminescence of the primary wafers is investigated. Moreover, the peak blue shift and luminescence intensity are measured by photoluminescence spectrum. The experimental results show that the peak blue shift reaches 62.5 nm when the annealing temperature is 890 ℃ and the annealing time is 10 min. A large peak blue shift is obtained by intermixing the primary sample, and the peak intensities are kept above 75% of the peak intensity of the original wafer in the annealing temperature range of 800--890 ℃ and 10 min annealing time.