Pb(Zr0.53Ti0.47)O3(PZT) thin film was fabricated on Pt/Ti/SiO2/Si substrate by chemical solution deposition method. Our results show a very great switchable ferroelectric diode effect (SFDE) in Pt-PZT-Au structure, which is more obvious and controllable than that in other ferroelectric thin films. The electrical conduction exhibits high rectifying behavior after pre-poling and the polarity of ferroelectric diode can be switched by changing the orientation of polarization in ferroelectric thin film. Our results also indicate that the SFDE in PZT film is highly dependent on remanent polarization and temperature. With the increase of remanent polarization, the forward current of bistable rectifying behavior observably reduces. Therefore, our measurement indicated that the biggest rectification ratio can reach about 220, which is found in 250K after +10V poling. By analyzing the conduction data, it is found that the dominant conduction mechanism of the SFDE in this sample is due to the space-charge-limited bulk conduction (SCLC), and Schottky emission (SE) may play subordinate role in forward bias voltage. Our observation demonstrates that SFDE may be general characteristic in ferroelectrics as long as proper electrodes chosen.