Taking into account fuzzy and grey problems of aircraft maintenance task type optimization， the evaluation index system and the decision model of maintenance task type were built by using interval grey uncertain linguistic variables. Then the optimization method for maintenance task type of military aircraft was proposed. An optimization example was demonstrated. As a result， the rank of task type alternatives and the comparisons of data indicate that the proposed optimization method is feasible and effective. Having used the proposed optimization method in an actual project of initial maintenance task type optimizations of a military aircraft， task types of 192 initial maintenance tasks were optimized successfully. According to the application result， the proposed optimization method promotes the reasonability of maintenance task types， thus possessing a favorable prospect in engineering applications。