针对空间磁场环境模拟线圈磁感应强度0~20 Gs连续可调,磁场稳定度优于1%的要求,采用前级电压源与后级电流源串联的主电路拓扑结构,结合电压双闭环控制和电流闭环负反馈控制的方法,实现了稳定的电流输出,减小了功率金属-氧化物半导体场效应晶体管(MOSFET)的功耗,提高了恒流源的效率.测试结果表明:恒流源输出电流0~10 A连续可调,霍姆赫兹线圈中心磁感应强度能达到20 Gs的设计要求,电流稳定度优于0.1%,磁场稳定度优于1%. Aiming at the requirement of 0 ~ 20 Gs magnetic flux density and the stability of magnetic field better than 1%, the main circuit topology of pre-stage voltage source and post-stage current source is used in combination with voltage double loop control and current Closed-loop negative feedback control method to achieve a stable current output, reducing the power MOSFET power consumption and improve the efficiency of the constant current source.The test results show that: the constant current source output current 0 ~ 10 A continuously adjustable, the magnetic induction of the Holm Hertz coil center can reach the design requirement of 20 Gs, the current stability is better than 0.1% and the magnetic field stability is better than 1%.