The invention provides a liquid damping time delayer for a fire protection safety control system. The liquid damping time delayer comprises a gas exchange device and a damping device which are connected mutually, wherein the gas exchange device comprises a gas inlet interface, a gas outlet interface, a small piston and a piston reduction end, wherein the gas inlet interface and the gas outlet interface are arranged at two ends of the gas exchange device and are communicated with the cavity of the gas exchange device; the small piston and the piston reduction end are arranged in the cavity of the gas exchange device and are connected mutually; the damping device comprises liquid, a liquid adding port, a large damping piston, a guide column, a display rod and a return spring, wherein the liquid fills in the cavity of the damping device; the liquid adding port is communicated with the cavity of the damping device; the large damping piston, the guide column and the display rod are positioned in the cavity of the damping device and are connected mutually; and the return spring is positioned at the circumference of a guiding column. By utilizing the liquid damping time delayer disclosed by the invention, the influence on time delay by the temperature can be reduced, the volume of a container can be reduced, and more reliability and safety can be improved.