Abstract: Aiming at the problems of narrow space in coal mines, high concentration of dust and gas, and the shortcomings of large-capacity electrolytic capacitors in traditional mining power supply rectification stages, such as short life and poor thermal stability, seriously affecting the reliability of rectifiers and the safety of underground coal mine personnel. This paper designs a VIENNA power factor correction (PFC) boost rectifier without electrolytic capacitors. By adding an improved buck-boost converter to the DC bus to decouple the active power in the DC link, the voltage ripple is forced to transfer to the auxiliary capacitor. So that the DC link capacitance is significantly reduced. Therefore, bulky electrolytic capacitors can be replaced with small film capacitors with high reliability. This article first introduces the relationship between the DC bus capacitors and DC-side voltage ripple of the VIENNA rectifier, then explains the realization principle of no electrolytic capacitors and the method of quantitative parameter design. Finally, the validity of the theoretical analysis and parameter design method is verified by simulation。