This paper studied the COM parameters extraction method based on the hierarchical cascading technique. By simulating on a finite-length SAW single port resonator on 42° rotated Y-X LiTaO₃ substrate, the COM parameters were extracted and the COM parameters datasets was established. A 1 200 MHz SAW filter with 3-IDT CRF hybrid structure has been developed. The results show that the amplitude-frequency response of the actual device is in good agreement with that of the simulated one,which verifies the feasibility of the method of extracting COM parameters in this article,and can be used to guide the design of SAW filters.