The globoidal cam mechanism is the core of the tool changer in CNC machines. Its dividing error will directly affect the precision of the tool changer and the machining accuracy of CNC machines. To reduce the dividing error of globoidal cam, the key problem is establishing an evaluation method for its dividing error. Considering the unsound problems of the existing evaluation methods, this paper adopts the fuzzy comprehensive evaluation method based on entropy, and establish the evaluation indexes from lateral error indicators, longitudinal error indicators and the dynamic indicators this three aspects respectively. Then the dividing error of globoidal cam could be evaluated. Through the case analysis, the proposed evaluation method and indexes for the dividing error of globoidal cam in this paper are proved to be effective.