The invention discloses a brake device of an anchor mooring positioning winch, and belongs to the field of winch fittings. The brake device comprises a spring oil cylinder, a tight-side brake band, a loose-side brake band, an oil cylinder pushing rod, a manual emergency pushing rod, emergency pins, a pivot-point dowel pin and a drive device, wherein a first end of the oil cylinder pushing rod can be rotatably connected with a second end of the loose-side brake band; a second end of the oil cylinder pushing rod can be rotatably connected with a piston rod of the spring oil cylinder; the middle part of the oil cylinder pushing rod and a first end of the manual emergency pushing rod can be rotatably connected with the pivot-point dowel pin; the pivot-point dowel pin can be rotatably mounted on a rack; a drive device is mounted on a second end of the manual emergency pushing rod; emergency pin mounting bases are separately mounted on the manual emergency pushing rod and the oil cylinder pushing rod; the emergency pins are detachably inserted into the emergency pin mounting bases; and the drive device is configured to drive the second end of the manual emergency pushing rod to rotate by taking the pivot-point dowel pin as a pivot point. The brake device can open braking of the anchor mooring positioning winch when a hydraulic system loses efficacy.