Based on Micro Inertial Measurement Unit (MIMU), the integrated velocity strapdown testing system was researched. The system was designed with a variety of new design methods, such as micromachining, ASIC and system integration. Both the working principle and the structure of the system were described. As an example of its application, the attitude of the separation process of a certain flying object and its mantle was tested by the system and the relevant curves based on the tested data were presented. Finally, the potential application of MIMU in the area of military and its market prospects were predicted.