Abstract: Compared with traditional reciprocating compressor, linear compressor is characterized by compact structure, small volume, low energy efficiency and high efficiency. The application of linear compressor gradually turns to refrigerator, air conditioning and civilian refrigeration equipment from aerospace and military areas. The design condition of moving-magnet linear compressor is determined. The theoretical capacity, piston stroke, piston diameter, equivalent stiffness and mass of motor are obtained. And the influence of design parameters, such as the mass of moving magnet linear motor and equivalent stiffness, is analyzed based on Ansoft Maxwell 2D. The change curves of current, copper loss, iron loss, stroke of piston, input power, electromagnetic force, specific force, power factor and motor efficiency are obtained. The results show that the efficiency of the linear motor is highest when the mass of the motor and the equivalent stiffness are at the design values.