Objective To evaluate the dietary quality of flight crew by military diet balance index （DBI） and provide basis for their dietary guidance and nutritional intervention.Methods Dietary survey was carried out by weighting method in three air force troops. The dietary quality of flight crew was evaluated by military DBI.Results Compared with GJB 826B-2010 （Dietary Ration for Soldier）， the intake of cereal and soybean met the standard， the intake of red meat， egg， plant oil and fruit was above the standard， the intake of other kinds of food was below the standard. The intake of vegetable， edible fungus， poultry meat， fish and shrimp， milk was insufficient， reaching 84.00%， 61.68%， 54.59%， 45.15% and 36.99% of the standard respectively. Compared with the recommended intake of the general population in the dietary guidelines for Chinese residents （2016）， the intake of salt was over the standard， the intake of added sugar was below the standard. Compared with GJB 823B-2016 （Dietary allowances for military personnel）， the intake of zinc， vitamin A， vitamin B₁ and vitamin B₂ was below the standard， reaching 89.85% 87.53%， 69.33% and 64.33% of the standard respectively. The intake of sodium， iron and vitamin E was above the standard， reaching 232.82%， 241.07% and 353.77% of the standard respectively. The energy supply ratio of protein， fat and carbohydrate was 17.44%， 43.87% and 38.71% respectively， which was obviously unbalanced， showing a “high fat and low carbohydrate” pattern. The food quantitative results were basically consistent with the military DBI scores， showing a slight imbalance.Conclusion The dietary pattern of the investigated flight crew was unreasonable； some of the food and nutrients intake were insufficient； the military DBI score showed that the dietary pattern was slightly unbalanced. The dietary pattern should be further adjusted， and the nutritional health education should be strengthened to promote reasonable nutritional behavior.