At present, income in farmers’ training evaluation can not reflect the real connotation of training and the scientific evaluation index system is lacked. Based on this, it is concluded that evaluation of farmers’ training is composed of demand evaluation, process evaluation and effect evaluation. Farmers’ training evaluation system is evaluated including four grades of index. Among them, the third grade index include demand investigation, satisfaction degree of peasant household, satisfaction degree of peasant household, organization degree, talent benefit, economic benefit, social benefit. The fourth grade index is the probability of demand investigation, training method, training content, training time, training textbook, teaching facility, tracking service, plan establishment, trainee, trainer, training evaluation, knowledge understanding degree, behavior change rate, growth rate of unit yield, growth rate of unit income, growth rate of output per worker, increasing rate of organization degree and participation degree. Connotation of evaluation index and the mathematical expressions of some indices are described in order to correctly evaluate the effect of training, to improve the quality of training, and to establish the training based on science.