A transaction processing client based on a trusted execution environment is disclosed. The client verifies a server in a secure environment, obtains a public key of the server upon successful verification, generates a session key and encrypts the session key using the public key in the secure environment, transmits the encrypted session key to the server in a normal environment, encrypts pre-obtained transaction information using the session key in the secure environment, and transmits the encrypted transaction information to the server in the normal environment. The present disclosure effectively ensures the security of user login information and user private information.