The invention discloses a high-speed feed safety-brake mechanism which comprises an oil cylinder arranged at the braking position of a high-speed linear feed component, and the oil cylinder is provided with an oil discharge oil and an oil feed hole; the oil feed hole is provided with an oil feed one-way valve, and the oil discharge hole is provided with an oil discharge one-way valve; and a piston rod of the oil cylinder is arranged in the motion direction of the high-speed linear feed component, and the outer end of the piston rod is dead against the high-speed linear feed component. In the invention, external hydraulic oil is stored firstly; then, in the process of braking, after a linear motion component contacts the piston rod, the piston pushes the oil in the oil cylinder to be discharged from the oil discharge hole, thereby achieving an effect of buffering and reducing an impact force generated in the process of braking; and finally, after the oil in the oil cylinder is completely discharged, a braking effect is achieved.