To understand blades' impact on the flow field distribution of the new vane current generation device based on the device model of Shanghai Ocean University, FLUENT software was used to numerically simulate the flow field. Moreover, the velocity and pressure contours of different blade shapes were obtained.Through the comparison of different blade shapes' velocity and pressure distribution,we found different blade shapes can play a certain role in changing and developing the exterior flow field and operating the vane current generation device smoothly. The flow field analysis results fully confirmed that the reasonable design of the blade shapes can play an important role in force tolerance of the generation device and improving the flow distribution, and also provided reliable theoretical reference for the optimization of the device.