This paper conducted a survey to obtain the inputs, outputs and managerial data of the tea plantations in Pinglin area, and then used the non-radial Russell measure DEA to evaluate the technical efficiency of tea farms. The results indicated that the average overall inefficiency score is 0.372 in which the inefficiencies are mainly from the use of pesticide and fertilizer. Therefore, it means that tea plantations have room to improve by 37.2% on average and the improvement of the use of pesticide and fertilizer is more important than other input uses. The comparisons of different groups of farmers showed that younger farmer, specialized production, and planting just two varieties of tea are helpful for the tea production in Pinglin. In addition, it is found that optimal production scale of the farms is about 2 hectares.