Turnip is a kind of perennial rhizome plant that belongs to cruciferae, which is rich in nutritional value and has function of disease prevention and health care.At present, the fresh and dehydrated turnip has bright market prospects and great demands.Traditional drying methods have normal pressure air drying, microwave drying, vacuum freeze drying and far infrared drying.In order to solve the problems of low efficiency, high energy consumption, complicated operation and the poor quality of dry product existed in conventional drying equipment.This paper integrating characteristics of far infrared heating technology and vacuum drying, integrated on-line detection technology and automatic control system, intelligent far-infrared vacuum dryer was designed and optimized.Far-infrared vacuum drying has the advantages of high thermal efficiency, short drying time, low energy consumption and better keep nutrition of fresh food, which is a hot drying technology of fruit and vegetable in recent years.During the drying process, material weight,material temperature, heating temperature, the vacuum degree inside warehouse, the warehouse humidity and energy consumption can be real-time monitored by the dryer.The full drying process automation and Intelligence was realized through the dryer.The fresh turnip harvested in this year as test material, combining theoretical analysis and production practice, and analysis the results of single factor experiment, selected heating temperature X1(60 ℃ ~80 ℃), vacuum in the warehouseX2(3000Pa~4000Pa), and material thicknessX3(4mm~ 10mm) were used as main test factors.Dehydration rate, rehydration rate, and VC mass ratio of dried product as test indexes.Using the quadratic general rotary unitized design approach, the influence and change law of far-infrared vacuum drying on drying turnip was studied.Analysis of interaction effects and regression model on the effect of the obtained experimental data, the regression equation was established, and the objective function optimization, optimized results adopt the integrated balance method to identify the optimal combination: the vacuum is 3000 Pa, the heating temperature is 70℃, and the material thickness is 7 mm, the optimal value of dehydration rate of turnip dried products is 25.23 g/m2·h, the optimal value of VC mass ratio is 2.05 mg/g, and the optimal value of rehydration ratio is 3.95.Under the condition of the process parameters, the dry efficiency can be improved effectively, and the loss of the nutrient components in the dry turnip can be reduced,and the quality of the dried product can be improved.Finally, the turnip dry products were observed by SESM and the results were analyzed.The result is: through the infrared vacuum drying of turnip, the cell wall breakage rate, cell deformation rate, and low profile shrinkage rate are lower;the surface smoothness preservation rate is higher;the cell tissue preservation rate is more than 80%, and the cell breakage and distortion is less.And the microscopic morphology of cell was kept well.Under this condition, the original organization and structure of the sample are truly reflected, the better drying effect was achieved, the sensory quality of dried products was guaranteed.This study provide a technical basis for the intelligent far-infrared vacuum drying technology applying for fast drying of high moisture materials and a reference for improving the quality of the far-infrared vacuum drying of turnip.