Abstract: Objective: The sweet potato leaves was processed into powder as a natural food additive to increase its nutrition and varieties. Methods: The optimal drying process during the sweet potato leaves powder processing were obtained through single factor screening,orthogonal experiments and pilot-plant experiments. Results: The vacuum drying was the best method including the condition of the temperature of 60 ℃,vacuum degree of 0.09 MPa and 75% loading capacity,without the color-protecting techniques.The vacuum drying was highest retention in obtain chlorophyll.Conclusion: The chlorophyll content and colour of sweet potato leaves powder was unable to improve through color-protecting techniques,but the better chlorophyll content and color of sweet potato leaves powder was obtained just by vacuum drying method.