The invention provides a power capacitor and a vibration and noise reduction device thereof, and the vibration and noise reduction device is arranged between a capacitor core and a box body in a manner of being corresponding to the upper and lower end faces of the capacitor core, and comprises a core bracket for supporting the capacitor core, a bottom plate arranged on a box body, and a pluralityof vibration isolation devices arranged between the core bracket and the bottom plate. Each vibration isolation device comprises a sleeve fixedly installed on a bottom plate and provided with a hollowpipe cavity; a spring piece which is made of an elastic material and covers the tube cavity, wherein the edge of the spring piece is fixedly arranged on the sleeve, and a matching structure is arranged in the middle area surrounded by the edge; a connecting shaft which is matched with the matching structure, wherein the top end is connected with the core bracket. The spring piece has higher radial rigidity and lower axial rigidity, so that the problem that the original capacitor core is suspended and collided in oil is avoided; and a good vibration isolation and reduction effect is achieved through the structure and the viscous effect of oil, and finally the purpose of noise reduction is achieved.