In this letter, 2-m Pb0.97La0.02(Zr0.75Sn0.18Ti0.07)O-3 antiferroelectric thick film with tetragonal structure was prepared. The effects of operating electric field, temperature, and frequency on the thermal-electrical energy harvesting capacity of the film were studied by using the Olsen cycle. The results demonstrated that giant energy harvesting effect could be realized in the antiferroelectric thick film. The maximum harvestable energy density per cycle of the film was about 7.8J/cm(3) at 1kHz, which was the largest reported value to date. The corresponding energy harvesting efficiency was 0.53%. Moreover, the film had a low leakage current density (about 7.3x10(-7) and 3.9x10(-5)A/cm(2) at 25 and 200 degrees C, respectively), which was favorable for its application in the devices of the thermal-electrical energy harvesting.