In this paper， numerical simulation is used to analyze the effect of the trailing edge of the stationary blade sawtooth on the 3.5-stage compressor， and the influences of shape and positions of the sawtooth on the compressor speed. The results show that the full blade with high opening on the trailing edge of the inlet guide blade can broaden the stable range of the compressor at 90% speed， and barely impact the pressure ratio and efficiency. But it has little effect the compressor at 100% speed. In this study， a sawtooth with a small tooth width is better than that with a large tooth width， and a sawtooth with full high-opening blades is better than that with partial opening tip. This study deepens the understanding of the effect of serrated trailing edge blades on compressor performance， and provides a reference for research on improving compressor stability.