The highly integrated multifunctional microsystem technology has made a great impact on communication, sensing, processing and actuating of information systems. However, the thermal management issues of microsystems restrict its further development. This paper presents the initiatives of America's thermal management for microsystems and reviews the advances of thermal management technology for microsystems based on heat conduction and liquid cooling techniques. An active and efficient thermal management method for microsystems based on piezoelectric actuation is also presented in this paper, and the principle test verification has been implemented by setting up the test prototype. The proposed technology can be applied to the thermal management of RF microsystems such as microwave/millimeter wave tile T/R module with high power.