Abstract: By studying the processing technology of pachyrhizus yoghurt and optimize it by single- factor experiment and orthogonal test method, we aim to provide technical references for the production. Taking pachyrhizus and fresh milk as main raw materials, single factor experiments were carried out with bacillus: cocci, inoculation amount, pachyrhizus: milk, sugar addition amount, fermentation time and fermentation temperature as factors. Then four factors including bacillus: cocci, inoculation amount, pachyrhizus: milk, sugar addition amount were selected, and L9(34) orthogonal experiment method was used to optimize the technological condition of pachyrhizus lactic acid fermentation with pachyrhizus yoghurt sensory as the standard. The best fermentation condition and the recipe are as follows: bacillus: coccus= 2:3, pachyrhizus: milk= 2:3, inoculation amount 5%, sugar content (in sucrose) 6%, fermented temperature 43℃,and fermented time 4 hours. The study improves the application of pachyrhizus, enriches the types of yogurt, and meets the need of the market.