ZnO is one of the most popular materials in UV photodetectors, but its low switching and long attenuation time seriously hinder its practical application. In this work, the performance of PZT/ZnO planar photodetectors is optimized by using the ferroelectric polarization of PZT thin films. The results show that the residual polarization field of PZT affects the electron arrangement in ZnO film, making ZnO in a depleted state, reducing the dark current of resulted photodetectors, and influencing the carrier life. By inhibiting recombination, the photocurrent is increased, and the switching ratio of the ZnO photodetector is increased by 5 times, and more importantly, the optical responsivity increases by 7 times to 1.015 A/W. This work provides a simple and feasible method for ferroelectric polarization to control the performance of two-dimensional material photodetectors.