Abstract: Magnetically controlled shape memory alloy(MSMA) is a new kind of functional material. A self-sensing actuator developed by using its reversible property can realize bidirectional conversion between mechanical force and electromagnetic signal. Based on theoretical analysis and finite element software Ansoft Maxwell, in order to increase the air gap flux density, reduce the excitation power and magnetic circuit leakage as the optimization objectives, the air gap width, core structure, MSMA material selection and other aspects of the optimization design and simulation are studied. The self-sensing actuator with optimized design has more reasonable structure, more uniform magnetic field distribution and better overall performance. The experimental results show that the induced voltage amplitude and signal stability of the self-sensing actuator are improved, which verifies the correctness and rationality of the structure optimization design of the self-sensing actuator.