The invention provides a disc separator. A separator main body is in a pot-type structure and internally and horizontally provided with an upper-layer separator and a lower-layer separator; an inlet pipe arranged on the side surface of the separator main body extends into a cavity of the upper-layer separator; the upper-layer separator and the lower-laye separator are both in upper opening open-type structures and opposite to each other; the area of an opening of the upper-layer separator is smaller than that of the opening of the lower-layer separator; and a guide pipe is vertically arrangedat the bottom of the lower-layer separator and communicated with the cavity of the lower-layer separator. When the disc separator is in use, a gas-liquid mixing body is out of an electrolytic cell and enters the upper-layer separator through the inlet pipe for primary gas separation, and liquid overflows from the hackly position of the upper-layer separator and then overflows to the lower-layer separator for secondary separation and then flows into liquid through the guide pipe so as to reduce the moisture content of a gas and further cool the temperature of the liquid, therefore sufficient gas-liquid cooling and separation is realized.