The embodiment of the invention provides a hydraulic safety valve. The hydraulic safety valve comprises a funnel-shaped drainage part, wherein the first end of the drainage part is connected to the inner wall of a suspension type separation plate, the second end of the drainage part points to an opening in the top of a connecting pipe, the outer diameter of the second end of the drainage part is smaller than or equal to the inner diameter of the connecting pipe, and the drainage part is used for draining condensed water or condensate oil into the connecting pipe. According to the hydraulic safety valve, the risk that condensed water or condensate oil flows into sealing liquid from the side wall of the suspension separation plate can be reduced, the volume of the sealing liquid in the hydraulic safety valve is kept within a normal range, and the use safety of the hydraulic safety valve is improved.