The invention relates to a fluid damper. The fluid damper comprises an upper part and a lower part which are mutually independent; the upper part of the fluid damper comprises an upper disc flange, a first permanent magnetic block and a first pressing block, wherein the first permanent magnetic block is fixed in the upper disc flange through the first pressing block; and the lower part of the fluid damper comprises a disc, a lower disc flange arranged opposite to the disc, and a hydraulic cylinder for connecting the disc and the lower disc flange in a leakage-proof manner, wherein the lower disc flange, the disc and the hydraulic cylinder form a closed leakage-proof space. In the invention, magnetic force and a spring are used for pushing a piston to move in the damper, and when the piston moves, damping fluid flows through a small circular through hole on the piston in an energy consumption manner, so that an effect of controlling vibration is achieved.