The invention relates to a battery protection circuit used for controlling power supply to a system by the battery. The battery protection circuit comprises a sensing circuit and a control circuit. The sensing circuit comprises a triaxial acceleration gauge which is used for sensing the position changes when the battery is in an unstable state. The output voltage of three output ends of an Axis X, an Axis Y and an Axis Z in the triaxial acceleration gauge change with the position changes of the battery. The output voltage of the three output ends of Axis X, the Axis Y and the Axis Z in the triaxial acceleration gauge at last generate control voltage to the control circuit. When the battery is in the unstable state, the control voltage switches off the control circuit to prevent the battery from realizing power supply to the system. When the battery is in a stable state, the control voltage switches on the control circuit to lead that the battery canot realize to supply the power to the system, thus achieving the aim of avoiding the generated electrical spark due to the power supply to the system with an unstable contact when mounting or dismounting the battery.