This article, on the basis of the magnetically levitated pumps developed by Ibaraki University, talks about fluid dynamic analysis of pump and optimization of parameters of the impellers. The pump uses blood as medium, with a flow rate Q of 5L/min, a pressure head H of 100mmHg. By using software of ANSYS CFX, the article analyzes the effect of shape, angle, height, length and thickness of the impeller on performance chart and fluid field distribution inside the pump. To fulfill the human requirements in blood pump, an optimization analysis is conducted to improve the uniformity of fluid field, reduce power and efficiency of the pump. As result, meeting the flow and pressure head condition, single curvature impeller is found to have lower speed, better efficiency and more uniform flow field, this helps to prevent the generation of thrombus and hemolytic.