Abstract: The total dose effect is one of the essential factors restricting the space applications of COTS products. In order to meet the requirements of high performance, miniaturization and radiation-robustness of electronic systems in the space applications, a total dose reinforcement scheme for a SiP (system in package) micro-system based on COTS devices is proposed, and a SiP micro-system is developed. In order to verify whether the micro-system can meet the needs of the applications in the space environment, a comprehensive evaluation method combining the model analysis with the total dose radiation test for the SiP micro-system is proposed. In view of the fact that the micro system is a combination of the equipment and the devices, the overall model evaluation is carried out on the equipment firstly, and then the test evaluation is carried out for the devices, thus the evaluation efficiency is improved with engineering benefit. It is shown through the ⁶⁰Co radiation test that the anti total dose capability of the SiP micro-system is not less than 150 krad(Si), which can meet the application need of related tasks. The above-mentioned total dose reinforcement scheme and the total dose capability evaluation method for the SiP micro-system may be used in the development of related micro-systems.