Abstract: If a tower crane is located at the top of a frame structure,the steel beams will be installed under the crane to undertake its weight.The body of the crane shall be connected with the original beams and slabs of the roof.The overturning moment of the crane will be counteracted.The internal force of the steel beams will be analyzed by exact mechanical method.By the results the correct type of steel beams will be chosen.At the same time the correct connection between the framework columns and the steel becuns will be ensured.Furthermore,the influence of this crane on the original building is also considered and calculated.