A fuzzy structured element method is applied to deal with fuzzy number intuitionistic fuzzy multi-criteria decision
making problems with incomplete certain information on criteria’s weights. Based on the representation of fuzzy structured
element of fuzzy number intuitionistic fuzzy set, the method of fuzzy structured element of fuzzy numbers’ comparison
and sequencing, and the score function and distance measure of intuitionistic fuzzy numbers, the score function and
distance measure of fuzzy number intuitionistic fuzzy numbers are defined. Furthermore, two multi-criteria decision making
approaches are proposed, such as the score function method, and the technique for order preference by similarity to ideal
solution(TOPSIS) method, in which the criteria values are fuzzy number intuitionistic fuzzy numbers, and the criteria weight
information is incompletely certain. Finally, an example is given to show the feasibility and effectiveness of the proposed
methods.