The invention discloses a line protection circuit, and the circuit is used in an intelligent mobile terminal. The intelligent mobile terminal comprises an interface circuit and central processing unit, wherein the interface circuit is connected with the central processing unit through a data transmission line. The line protection circuit at least comprises a first-stage protection circuit and a second-stage protection circuit, which are used for protecting an abnormal voltage or current, wherein the first-stage protection circuit and the second-stage protection circuit are sequentially connected to the data transmission line from the interface circuit to the central processing unit, and the types of the first-stage protection circuit and the second-stage protection circuit are different. By applying the embodiment of the invention, the circuit can solve the problem of insufficient abnormal current or voltage protection capability in the existing mobile terminal.