The invention discloses a login method and device, a terminal and a network server, and belongs to the field of communication. The login method comprises the steps of obtaining an account number to be logged in and a first password to be logged in, judging whether the first password is the same as a local password bound with the prestored account number or not, uploading a second password corresponding to the prestored account number to the network server to conduct matching if the first password is the same as the local password bound with the prestored account number, and logging in the account number if the matching is successful. Due to the fact that the user-defined password, namely the first password is introduced, complexity generated when the practical login password, namely the second password is input is avoided, insecurity generated when the practical login password is remembered on a terminal is avoided, therefore, rapidness, convenience and safety of login are improved, and user experience is strengthened.