In order to find a precise and effective method to characterize micro-hardness of Au coating to meet the demands for space applications. The micro Vickers hardness test method and Nano-indentation test hardness method were selected to characterize micro-hardness of Au coating under different test position and different force conditions. According to the requirements of the relevant technical standards, the feasibility of the test method is analyzed. The results showed that: The optimized micro Vickers hardness test parameters and results meet the QJ482 technical standard requirements. The depth of indentation is less than 1/7 of the thickness of the Au coating, the impact of matrix material on hardness test results is avoided. The test method is feasible and the results are valid.