Based on the problem of the micro axial turbine efficiency being reduced at low aspect radio and low Reynolds number, regarding a high pressure turbine of a 200 kW micro turbine generator as the object of study, the micro bow axial turbine stator design technology is researched using the numerical simulation method at low aspect radio. When the turbine stator aspect radio is 0.88, the effect of positive bow stator and J bow stator on the turbine flow field is analyzed and compared, and the results show that: The positive bow stator enlarges the stator exit flow angel on the tip and the rotor tip clearance loss, so drops the efficiency. The J bow stator restrains the flow separation of rotor in the mid and improves the overall efficiency. Then, the effect of bow height and bow angel on the J bow stator is studied, and the result indicates the J bow stator with big bow height and little bow angel can improve the mass flow of hub. At the same time, the passage aerodynamic load and the exit flow angel are reasonably distributed, which can improve the turbine internal flow. When J bow stator′s bow height is 1 and bow angel is +5°, the stage efficiency and the mass flow achieve 0.852 and 1.205 kg/s, and increase by 0.77% and 0.96% compared witch original ones, respectively.