Abstract: When the wind tunnel starts or ends running, there is a large impact load which could damage the flutter model easily. In order to solve the problem, a supersonic flutter insertion system is developed in FL-23 wind tunnel of CARDC. During the flutter tests, the insertion system pushes the model into the flow after the impact load disappears, and at the end of the tests or if the flutter occurs, the insertion system pulls the model back quickly. The test results show that the insertion system could protect the flutter model from damage effectively and ease the intensity limit of the model. The dynamic pressure achieved from the subcritical prediction is close to the flutter test result. As a conclusion, a practical supersonic flutter testing platform has been established in CARDC.