Potato vermicelli was prepared with potato whole powder, egg and water as main raw materials, which mixed in a certain proportion and stirred to pulp. After entering the mold, the pulp was cooked at constant temperature, cut into strips, dried and cool down. The influence of four factors, including the addition amount of eggs and water, cooking method and drying time, on the quality of instant potato vermicelli was investigated. The results showed that the optimum process conditions were the mass ratio of potato whole powder, water and egg liquid was 1∶1∶0.7, the constant temperature 100 ℃ and drying time 35 min. The optimum rehydration time of instant potato vermicelli was 5 min, both of the total number of microbial colony and number of coliform meet the national sanitary requirements, and the shelf life reached 450 d. This technology improves the quality of potato flour and enhances added value of potato flour.