The air discharge plasma technology has become an important research direction of plasma medicine. In general, the plasma discharge power supply takes the mains power or a large-scale regulated power supply as its input. This kind of power supply is too large in size to meet the application conditions of portable, wearable and attachable plasma generators, which limits the practical applications of the plasma technology in biomedical field. Under this research background, a plasma power supply with a piezoelectric ceramic transformer as its core was designed and studied to meet the requirements of miniaturization and portability for power supply. The size of this power supply was 50 mm×15 mm×8 mm, and its weight was 12.1 g. The power drive circuit adopted a chip-driven oscillating half-bridge circuit, and its main circuit included a step-up Boost circuit and a step-down Buck circuit. The results of no-load and on-load discharge tests show that when the power supply was supplied with 3.7 V power input, the no-load discharge voltage can be adjusted from 200 V to 2.2 kV, the output frequency was 52 kHz with fluctuation of 1 kHz, the maximum output power was 7 W, and the power weight ratio was 580 W/kg, which was better than the common plasma power supplies on the market. Through experimental tests, it is found that the application of this power supply can make SDBD and FE-DBD plasma generators discharge to produce cold plasma. Its miniaturization and portability are of significance to the application of wearable and attachable plasma generators.