Hemolysis is the main complication of blood pump ventricular assist. Aiming at the most widely used rotary blood pump, this paper summarizes and analyzes the main influencing factors of hemolysis: the shear stress and exposure time of red blood cells. In addition, local negative pressure, temperature and other factors will also affect hemolysis. And then this paper summarizes the research progress of prediction and improvement methods of hemolysis performance: different combinations of hemolysis prediction model and empirical constant will cause different differences in prediction results. Compared with the power law model, the OPO model can consider the complexity of turbulence more. The research on improving the hemolysis performance mainly focuses on the optimization of the blood pump structure (such as pump clearance, impeller, guide vane, etc.). A few scholars have also studied the hemolysis performance of the blood pump through the reasonable selection of the speed control mode of the blood pump and the blood compatibility materials. Finally, the paper discusses the limitations of current hemolysis research and prospects for future research.