The invention relates to a cooling device, in particular to a fast cooling device for iron blocks for hardware manufacturing. The fast cooling device for the iron blocks for hardware manufacturing is high in cooling efficiency and comprises a guide plate, a top support, a right support, a first spring, a first sliding rail, a first water tank, a piston, a connecting rod, a first wedge block, a first sliding block, a second sliding rail and the like, wherein the guide plate, the first water tank and the first spring are sequentially arranged at the bottom of the top support from left to right, the guide plate is provided with a guide hole, a first hard pipe is arranged at the upper part of the left side of the first water tank, and the piston is arranged inside the first water tank. According to the fast cooling device, an electric push rod is adopted; and through the linkage effect, after the electric push rod is started, a placement ring is driven to move rightwards to the part below the first hard pipe and a second hard pipe, the piston is driven to move upwards, and a stop block is driven to move rightwards.