The embodiment of the invention provides a protection circuit, a control method of the protection circuit, a telecommunication plug-in shelf device. The protection circuit comprises a sampling module, an equipment power supply loop, a
processing module, a judging module and a drive module, wherein the sampling module is used for sampling from the equipment power supply loop to obtain a sampling
signal, the equipment power supply loop is a circuit between a power supply in the telecommunication plug-in shelf device and at least one slot in the telecommunication plug-in shelf device, the
processing module is used for accumulating and maintaining the sampling
signal and obtaining a corresponding
charge voltage after the sampling
signal is accumulated, the judging module is used for comparing a charging
voltage with a preset reference
voltage and sending a
control signal to a drive module when the difference value beween the charging
voltage and the preset reference voltage is less than or equal to the preset threshold, and the drive module is used for receiving the
control signal sent by the judging module and
cutting off the equipment power supply loop according to the
control signal. According to the technical scheme of the embodiment of the invention, arc can be rapidly extinguished, the arc
discharge energy is prevented from being converged and enhanced, the fire is avoided, and the safety of the telecommunication plug-in shelf device is enhanced.