Considering the key technologies to enhance the accuracy of micro-EDM, a micro-EDM system and some techniques are researched. In this system, a micro-energy pulse power supply whose open voltage and capacitance can be adjusted is developed. The detection and control subsystem of the machining process is designed and applied. A simple method of machining high precision microelectrodes is adopted. The forming mechanism of the gap in EDM process is analyzed theoretically. The processing experiments are carried out on the system, and the results basically coincide with the theoretical analysis. The experimental results of machining microelectrodes and micro holes show that the Ø4.5±0.5μm microelectrodes can be ground, and the Ø6±2.0μm micro holes can be drilled.