Abstract: The discharge voltage of traditional depositing power supply cannot be continuously adjusted,which limits the application range of electro-spark deposition and the efficiency of electro-spark deposition. In order to overcome this shortage,a digital control of capacitance charge-discharge pulse in electrospark deposition power supply was developed. This power supply consists of CPU,rectifier and filter circuit,charge and its drive circuit,charge voltage comparison circuit,discharge and its drive circuit,motorial electrode,etc. With alternate charge and discharge process of this power supply,discharge voltage and discharge energy as well as discharge frequency can be adjusted steplessly. Experimental results show that the SCR of this power supply can be shut off safely when a short circuit occurs between the electrode and the workpiece,which greatly improves the efficiency of pulse output. The adjustment of discharge parameters is convenient,thus the power supply meets the requirements of various process condition.