The sacrifice layer release is the crucial process step to form the cavity structure of the cavity type film bulk acoustic resonator (FBAR),and the sacrifice layer release result directly determines the resonance characteristics of the cavity type 〖HJ*4/9〗FBAR. Based on the insight of the functional and structural characteristics of the air gap in the cavity type FBAR,a novel process method named as the top down through via wet etching to fabricate the apertured cavity type FBAR is proposed. To validate feasibility of the novel fabrication method, the constant diffusion coefficient (CDC) model numerical iteration of sacrificial layers corrosion process was simulated by MATLAB,and the corrosion process was also simulated by Silvaco software.According to the simulation results,the optimum design of release window is proposed. The resonance simulation of FBAR without release window and with release window have been analyzed with FEA software ANSYS. Comparing the simulation results,it shows that the apertured FBAR still has quite good resonant characteristics,but the frequency of impedance zero point and impedance pole of the apertured FBAR are drifted to a higher frequency band;and the effective electromechanical coupling coefficient and the quality factor of FBAR are reduced.