A new technology of piezoelectric self-adaptive micro electrical discharge machining has been developed in this paper according to the characteristics of micro-EDM. Its working principle and the discharge characteristics are introduced, and it has been proved that the new technology can achieve micro machining. Using piezoelectric actuator as micro-feed mechanism, this new technology is simple in structure and can improve the discharging gap effectively. The discharge frequency and effective pulse utilization rate of the power supply is enhanced in machining. Experimental results show that this new technology can achieve good results.