Micro turbine engine has the advantages of light weight, small scale, high power density and no need of charging. It is the best choice of power source for micro mechanical equipment and has a good application prospect. The rotor diameter of micro turbine engine is in the range of more than 10 mm to dozens of mm. The design speed is generally from hundreds of thousands to more than one million rpm, and the power density target is within 100 W. The friction and lubrication problems of ultra-high speed micro bearing rotor system are the bottleneck of micro turbine engine. At present, gas lubricated bearings are mostly used in micro turbine engines. In this paper, the research status of micro turbine engine is classified and summarized, and the research results of gas bearing test system are reviewed, and the development trend of test technology is prospected.