Abstract:The vacuum freeze-drying technology of pitaya was studied，the technological parameters of vacuum freeze-drying were explored，and the added value of pitaya was increased.Orthogonal experiments were designed for three factors affecting vacuum freeze-drying to study the effects of different slice thickness，sublimation temperature and analytical temperature on the sensory quality and internal quality of pitaya fruit.The results showed that the optimal process parameters for sensory score optimization were as follows：thickness 8 mm，sublimation temperature 25℃，analytical temperature 50℃；The optimal process parameters for VC content score optimization were as follows：thickness 10 mm，sublimation temperature 25℃，analytical temperature 40℃；The horizontal combinations of the factors that had the greatest influence on protein content were as follows：thickness 8 mm，sublimation temperature 15℃，analytical temperature 45℃.The horizontal combinations of the factors with the greatest influence on the total dietary fiber content were as follows：thickness of 10 mm，sublimation temperature of 15℃，analytical temperature of 45℃；the horizontal combinations of the factors that had the greatest influence on the sugar-acid ratio were as follows：thickness of 10 mm，sublimation temperature of 20℃，analytical temperature of 50℃.Through comprehensive analysis，it was concluded that the optimal drying conditions of dragon fruit were as follows：thickness of 10 mm，sublimation temperature of 25℃，analytical temperature of 50℃，sensory score of dragon fruit was 95，VC content of 74 mg/100 g，protein content of 9 g/100 g，total dietary fiber content of 22.5 g/100 g，sugar-acid ratio of 64.37.