A protocol identification method and a protocol identification device are provided. The protocol identification method includes acquiring a performance index of protocol characteristic information according to characteristic conditions of the protocol characteristic information; calculating identification probabilities of the protocol characteristic information employed by DPI under a preset statistical strategy according to a DPI identification result; determining an optimal sequence of all protocol characteristic information in a DPI identification library according to the performance index and the identification probabilities of the protocol characteristic information; and performing protocol identification on a received message according to the optimal sequence. The optimal sequence for protocol identification is determined according to the identification probabilities, the protocol characteristic information with a high match success probability may be matched first, and the protocol characteristic information with a high match failure probability may be matched later, which thereby improves the protocol match performance.