Abstract: The principles of incident pulse shaping and the design methods of ideal incident pulse were studied for the dynamic tests of quasi-brittle SiC<sub<p</sub</Al composites with a 50% volume fraction of SiC particles under a constant strain rates loading with SHPB. The results show that a novel method by piling up the raw transit wave and the modified reflected wave to design the incident pulse is developed, and ideal incident pulses are achieved through reasonably designing the size of pulse shaper and controlling the bullet muzzle velocity. The pulse shaper designing should integrate the material properties of specimen, and the key of pulse shaping is to adjust the shape of pulse to be same with the shape of the raw transit wave. For SiC<sub<p</sub</Al composites the strain rate depends on the amplitude of incident pulse but not loading rate, and a platform in the incident pulse is needed for constant strain rate. Adjusting the shape of incident pulse to be trapezoid and making it similar with the shape of the raw transit wave of SiC<sub<p</sub</Al composites, lead to the composite specimen deformation at constant strain rate.