Because it’s not easy to adjust the control parameters in the analog current loop of artillery servo system and the capability of noise immunity is insufficient. Based on field-programmable gate array (FPGA), in this paper the hardware circuit and software codes of digital current loop are designed, and then dSPACE sweep testing, simulation analysis and performance testing have been carried out for the current loop. The results show that the digital current loop based on FPGA possesses superior performance and can meet the requirement of the artillery servo system.