Abstract: Lorentz force can control the flow of low-conduction fluid effectively,increasing lift and reducing drag, suppressing flow separation; however, the problem of control efficiency is the main bottleneck to restrict its application. In order to enhance its control efficiency, numerical simulation research had been carried out base on the flow control around hydrofoil using Lorentz force. Energy consumption of Lorentz force control had deduced on the basis of the law of conservation of energy; the amount of saving energy had calculated by using the lift and drag of hydrofoil. The control efficiency of the Lorentz force is defined as the ratio between saved power and used power. The control efficiency of lift increase and drag reduction under different working conditions had been studied. The results had shown that the control efficiency of Lorentz force index decrease with the increase of inflow velocity, and increase with the control time increase. To increase the input energy of Lorentz force actuator can enhance the control effect of Lorentz force, but cannot increase the control efficiency distinctly.