Compared to electrochemical supercapacitors, electrostatic supercapacitors have higher power density and reliability, but its energy density are low. In this paper, the MEMS electrostatic supercapacitor with high energy density were prepared based on the high dielectric constant CaCu₃Ti₄O₁₂(CCTO) film. Firstly, CCTO films were synthesized under the different sintering temperatures (700℃, 800℃, 900℃), through a sol-gel method on silicon substrate. The morphology, phase identification and crystalline of CCTO films were characterized using X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM) respectively. The results showed that the CCTO film has the best quality at 800℃. And then, we tested the I-V and C-V characteristics by the metal-insulators-semiconductor capacitor structure, getting the largest hreshold voltage and energy density, which have values of 47 V and 3.2J /cm₃. Meanwhile, the paper firstly proposed to research the phenomenon of dielectric charging in the high dielectric constant film and analyzed the influence on electrostatic supercapacitors.