The inherent relationship between the microstructure parameters and anti-impact strength is established by micromechanical strength and dynamic destruction criterion of eutectic composite ceramic. Firstly, in line with the microstructure characteristic of eutectic composite ceramic, the effective stress field of composite ceramic is computed by the interaction direct derivative estimate and sufficiently simplified calculation method. Secondly, according to equivalent inclusion method and Griffith micro-crack propagation theory, the micromechanical strength of eutectic ceramic composite is predicted. Thirdly, the dynamic destruction criterion of the comminuted zone is built by the unified pressure shear criterion. Finally, on account of the dynamic destruction criterion which is associative with microstructure, the calculated mode of anti-impact strength is obtained. The influence of microstructure parameters on anti-impact strength is quantitatively analyzed. Results show that decrease in interface defect size among eutectic grains and increase in eutectic grain stiffness will increase anti-impact strength.