A damping safety valve comprises a valve body and a valve rod, wherein the valve body is provided with a pressure fluid inlet and a pressure fluid outlet; one end of the valve rod elastically presses against the pressure fluid inlet tightly; the valve body is also provided with an airtight damping chamber internally-filled with damping liquid fully; the damping chamber is divided into a first damping chamber and a second damping chamber by a slipping flat arranged inside the damping chamber, wherein the first damping chamber and the second damping chamber are airtight mutually and the slipping flap is fixed on the valve rod; the valve body is also provided with a first drainback passage that is communicated with the first damping chamber and the second damping chamber; the valve body is also movably provided with an adjusting component used for adjusting the flow rate of the damping liquid in the first drainback passage; and at least part of the adjusting component is sheltered on the section of the first drainback passage and at least part of the adjusting component is exposed outside the valve body. The damping safety valve can effectively slow down instantaneous impulsive force in the instant of opening and closing the valve, thus reducing impact on pipe walls of the liquid, being capable of flexibly adjusting the delay time of the safety valve and precisely controlling instantaneous recoil force during unloading.