The present invention relates to a relay protection state online evaluation method based on a fuzzy support vector machine. The method comprises: obtaining the operation historical data of a smart transformer station relay protection device; performing pretreatment and fuzzification of the state evaluation factors according to the relay protection historical data; calculating the percentage residual life according to the touring and fault recordings, and generating a training sample set; performing regression training through the fuzzy support vector machine, generating a model, and performing state evaluation of the online monitoring data; and comparing the result with an artificial evaluation result, regulating the sample weight having differences of the evaluation result, repeating the flow, and obtaining a final state evaluation result. The relay protection state online evaluation method based on the fuzzy support vector machine avoid the dependence on the subjective factors and employs the advantages of the fuzzy support vector when different weight samples are processed so as to effectively solve the problem of the state evaluation of the smart transformer station relay protection device.