A piezoelectric accelerometer based on d33 mode was studied in this work. It is comprised of multiple cantilever beams to support a central seismic mass. The piezoelectric PZT thin films and interdigital (IDT) electrodes are designed to be deposited on the surface of beams. The PZT thin film was in-plane polarized and worked in d33 mode. The accelerometer was fundamentally analyzed and designed by using finite element method in ANSYS. Results showed that the presented micro piezoelectric accelerometer in d33 mode can offer higher voltage output over that in d31 mode, significantly improving the sensitivity without lowering the bandwidth.