Abstract: These days cubesat and micro-nano satellites are developing rapidly，while lack of appropriate mirco thruster system will constrain its evolvement，so we start the development of vacuum arc thruster.Through comparison，we choosed arc thruster of ring structure with enhancing magnetic，which can improve the performance significantly.This paper introduced the main working principle of thruster，through theoretical analysis and formula derivation structure parameters of core components were determined，and expounded the key technical problems of design method of thrust head structure and low voltage reliable ignition.Thruster structure design result shows that the thruster mass is only 300g and volume is 35 mm×25 mm×25 mm，having realized the miniaturization and lightweight.The design and function of the magnetic enhancement structure were described，and the design criterion of theoretical parameters was described，and the magnetic circuit of the structure was verified by Femm simulation software，and the magnetic circuit characteristics were tested by Gauss.By comparing the simulation results with the experimental results，the result shows that the design can meet the actual results.Preliminary experiments show that the thruster has reliable ignition and stable operation.