The invention discloses a crane hoisting mechanism with an extension sleeve, comprising a trolley frame, a steel
wire rope, a winding drum, a balance arm and a movable
pulley block. The crane hoisting mechanism is characterized in that the extension sleeve is composed of an extension sleeve
assembly IV, an extension sleeve
assembly III, an extension sleeve
assembly II and an extension sleeve assembly I, wherein the extension sleeve assembly IV is sequentially sheathed with the extension sleeve assembly III, the extension sleeve assembly II and the extension sleeve assembly I. The circumferences of the extension sleeve assemblies IV, III, II are respectively equipped with four stop blocks and four roller wheel assemblies which are alternately and uniformly distributed, wherein the installation
phase difference of the stop block and the roller wheel between the extension sleeve assembly IV and extension sleeve assembly III is 45 DEG, and the installation
phase difference of the stop block and the roller wheel between the extension sleeve assembly III and extension sleeve assembly II is zero. The extension sleeve assemblies I, II, III are respectively equipped with four guide rails I, II, III, which are uniformly distributed on the circumferences of the extension sleeve assemblies and are respectively and freely connected with the roller wheels on the extension sleeve assemblies II, III, IV. The upper
flange of the extension sleeve assembly IV is fixedly connected with the trolley frame; and the lower
flange of the extension sleeve assembly I is fixedly connected with a
pulley assembly, and the steel
wire rope is wound on the lower
flange which is fixedly connected with the balance arm by virtue of the movable
pulley block.