The rate-responsive pacemaker can help patients recover cardiac chronotropic function and adapt to different daily activities. The bioelectrical impedance technology is applied to predict human sinus heart rate under the modulation of autonomic nervous system and has demonstrated high reliability. In order to facilitate scientific research and improve industrial production efficiency of pacemakers, based on previous studies on modeling of right ventricular impedance(RVI), this paper designed a cardiac bioelectrical impedance simulator, including impedance generator circuit, microcontroller and graphical user interface(GUI). The designed device can output resistance ranging from 400 Ω to 1100 Ω, with resolution of 1 Ω and capacitance from 1140 pF to 1180 pF, with resolution about 1.27 pF. It can simulate the change of RVI and meet the demand for practical application.