Disclosed is a cell phone data encryption method, which comprises the steps of obtaining a PIN code which is input by a user, obtaining a SIM card code from a SIM card according to the PIN code, and combining the PIN code with the SIM card code to form a password string; and encryption source data using the password string, so as to obtain encrypted data. Also provided is a cell phone data encryption method. Through the manner mentioned above, the technical solution provided in the present invention can protect cell phone data.