The deformable mirror is one of the core units of the Adaptive Optics (AO) System. This article proposes a new voice coil actuator structure based on the principle of minimum magnetoresistance. The soft magnetic material-Permalloy is added to the traditional voice coil structure design to reduce magnetic leakage and thus improve output force and efficiency. The model is established by ANSYS Maxwell for simulation and the structural dimensions of each component are optimized. The results show that the actuator structure can generate a force of 3.4 N, an efficiency of 9.05N×W-1/2, and a response time of 0.03 ms. At the same time, it is found that the working influence between adjacent actuators is very small, so it is established that the coupling of deformable mirror is 11.7% when the actuator spacing is 15 mm, which meets the system requirements. This work lays a solid foundation for the development of deformable mirrors with large travel, fast response, low power consumption and high actuator density, which have good application prospects.