The invention discloses a method for hybrid encryption of OPC UA by RSA and BLOWFISH, and relates to industrial data communication and information security. The method is mainly applied to the securedata communication between an OPC UA client and a server, since the RSA requires a 1024-bit length key to implement fixed encryption, if the data are encrypted by the key of the RSA, the calculation amount is large, and the encryption time is long, therefore the key generated by the RSA by encrypting BLOWFISH is used, and the OPC UA data are encrypted by the key generated by a BLIOWFISH algorithm.By adoption of the method, the encryption efficiency of an OPC UA system is improved.