Flyers with wave impedance gradient can be regarded as a new kind of functionally graded material, which has come to show great potential for the application in dynamic high-pressure technology. In the present paper, a theoretical model of generating quasi-isentropic compression via the W-Mo-Ti system flyer was established, and the numerical simulation has been carried out. The results show that the design for flyers with graded wave impedance should conform to the parabolic or cubic function relationship of the change in the thickness. The thickness of target and the impact velocity should also be well controlled for creating a be tter quasi-isentropic compressive wave profile.