Abstract: In order to solve a series of problems,such as poor fitting process,long delivery cycle,weak carrying capacity and so on,caused by welding deformation of thin plate in the process of cruise ship construction,this paper utilized the TRIZ theory to investigate the welding deformation of thin plate.Firstly,a functional model of the welding process was established,and the influencing factors were quickly and precisely located by the mapping diagram of the causes of welding deformation;subsequently,the proposed invention principle was determined by combining with the contradiction matrix,so as to put forward the improvement.In addition,the application of TRIZ theory in controlling the welding deformation of thin plate on cruise ships provides a reference for the application in the construction process of cruise ships.