Continuous electrode configuration (CEC) has been widely used in piezoelectric energy harvesters (PEHs). A PEH with CEC works around the first resonance efficiently but it suffers from low efficiency due to cancellation effect around higher modes. The use of segmented electrode configuration (SEC) can avoid the cancellation effect around higher modes. To achieve this, the output from each electrode pair on the opposite sides of the strain node needs to be rectified separately. In such a case, the theoretical formulation for power estimation becomes challenging because of some nonlinear electrical components included. In this paper, a method based on combining the equivalent circuit model (ECM) and the circuit simulation is proposed to estimate the power outputs of the cantilevered PEH with the SEC. First, the parameters in the ECM considering multiple modes of the PEH with the SEC are identified from the finite element analysis. The ECM is then established and simulated in the SPICE software. The optimal power outputs from the PEH with the SEC are compared with those from the PEH with the CEC. The results illustrate the advantage of the SEC to enhance the power outputs of a PEH at higher resonance frequencies.