The essence of the type selection of the platform for ship repairing and maintenance at far sea is a decision-making with multiple fuzzy related attributies, including of operability, stability, timeliness, safety and economy. In order to reflect the decision-making intention of decision makers and integrate decision information more accurately in the platform selection process, a R-THIOWGA (related triangular hesitate intuitionistic ordered weighted geometric average) operator was built, and a new comparison rule of the triangular hesitate intuitionistic fuzzy number was also presented. A method of the group decision-making for type selection of ship repairing and maintenance at far sea was proposed, based on the R-THIOWGA operator. The application of the method was analyzed on Chinese Navy ship repairing and maintenance practically. The result shows that the R-THIOWGA operator is feasible for multiple fuzzy related attributes decision-making, and the self-propelled semi-submersible repair and maintenance ship is confirmed as the best platform type for China navy.