The invention discloses a network transmission data security processing method based on mixed encryption, which comprises the following steps: creating a pair of asymmetric encrypted public and private keys by a server; creating a pair of asymmetric encryption public and private keys by a client. accepting the request of the client by the server and saving the public key of the client to the background database according to the unique identification ID number, wherein the client needs to encrypt the data with symmetric key and asymmetric key to initiate the request; obtaining the request of the client to decrypt the data by the server, wherein the server needs to be encrypted with symmetric and asymmetric keys for data feedback; and decrypting the data by the client. According to the method, the data transmitted by the network are encrypted through the combination of asymmetrical encryption and symmetrical encryption, thereby realizing high safety and high reliability. The pseudo-random number generator is unique in generating process and troublesome to crack, which makes the symmetric encryption key more complex and improves the security effect. The method is unique, the design isclever and has good application prospects.