The invention discloses a pulley block for an overhead crane with hook. The pulley block comprises an outer protective shell and side walls, wherein the semi-circular outer protective shell is mounted at the bottoms of the side walls in a sleeving manner; limiting grooves are formed in the outer walls of tops of the side walls; rectangular springing cavities are formed in the inner walls of the side walls and communicate with the limiting grooves; a primary shaft and a secondary shaft are transversely mounted in middles of bottoms and tops of the side walls; main auxiliary wheels are mounted at two ends of the primary shaft; main reels C are mounted on the inner sides of the main auxiliary wheels; combined reels D are mounted on the inner sides of the main reels C in a sleeving manner; lifting hook side plates are mounted at two ends of the combined reels and longitudinally penetrate through the bottom of the outer protective shell; two ends of the secondary shaft are mounted in the limiting grooves in a sleeving manner; a shaft sleeve ring is mounted at the part, in the springing cavities, of the secondary shaft in a sleeving manner; T-shaped rods are mounted at the top and the bottom of the shaft sleeve ring; springs are mounted on the T-shaped rods in a sleeving manner; secondary auxiliary wheels are mounted at two ends of the secondary shaft in a sleeving manner; small rollers A are arranged on the inner sides of the secondary auxiliary wheels; and combined rollers B are arranged on the inner sides of the small rollers A. The composability is high and steel cable connection is stable.