Aiming at the multiple attributes decision making problem caused by intuitionistic triangular fuzzy number vectors’ projection, a method is proposed in which the attribute weights are completely known and the attribute values are in the form of intuitionistic triangular fuzzy numbers. From the angle of vector projection, the arithmetic of projection between two intuitionistic triangular fuzzy number vectors is given, then the alternatives are ranked by using the projection of the weighted attribute values of every alternatives on the fuzzy positive ideal point. In the end a numerical example is given out. The results show that this method is simple, clear and easy for use, and the work has an important applied value for multiple attributes decision making.