The invention discloses a disc brake for monitoring positive brake pressure, which comprises a brake disc, a brake shoe, a lining board, a disc spring, a hydraulic cylinder, a connecting screw, and a piston, wherein the bottom of the disc spring is provided with disc spring seat sensors which contact the small diameter of the disc spring, and the front part of the disc spring is provided with a disc spring seat sensor retaining ring; or contact positions of disc spring strips are adjusted when the disc spring strips of the disc spring are stacked, and the front part of the disc spring is provided with the disc spring seat sensors which contact the small diameter of the disc spring. The bottom or the front part of the disc spring is provided with the disc spring seat sensors in different directions by utilizing the limited space for placing the disc spring, installation dimensions of the disc spring seat sensors are the same as those of the prior disc spring seat of the prior brake, the disc spring seat sensors can be replaced on the spot, and the aim of directly monitoring the positive brake pressure can be achieved without changing prior performance parameters of the prior brake and structural dimensions of other parts, thereby greatly improving the reliability of the disc brake of a hoisting machine. The disc brake has the advantages of simple structure, convenient installation and maintenance, high measuring accuracy, and broad applicability.