A kind of catamaran crane with hoisting truss as connecting bridge structure has recently emerged on Qiantang River due to the prominent requirement of lifting and salvage in inland river and the difficulty of ship repair imposed by the situation of more ships than factories. The strength check of this new structure that is beyond the rules is a new problem in the ship inspection and certification. On the basis of relevant specifications, the analysis methods of the total longitudinal and local strength, total transverse and torsional strength, hoisting truss strength and supporting structure strength for this type of ship are presented and applied to the structural analysis of a 700 t crane ship. This method can be applied to the design and check of the same type of ship.