The invention relates to standby pumps and provides a grate cooler standby pump interlocking device. The grate cooler standby pump interlocking device aims to overcome the defects that in the prior art, when a grate cooler standby pump is changed over, other sections are shut down, and material blocking occurs. The grate cooler standby pump interlocking device comprises a power supply, a digital quantity input module, a power supply module, circuit breaking devices, micro-type relays and middle relays, the positive electrode and the negative electrode of the power supply module are connected with one ends of the circuit breaking devices and one ends of the coils of the micro-type relays respectively, the other ends of the circuit breaking devices are connected with the other ends of the coils of the micro-type relays, one ends of the normally open contacts of the micro-type relays are connected with the power supply, two ends of the coils of the middle relays are connected with the other ends of the normally open contacts of the micro-type relays and the ground respectively, and two ends of the normally open contacts of the middle relays are connected with the digital quantity input module and the ground respectively. Grate cooler hydraulic pumps are made to correspond to the circuit breaking devices respectively, the circuit breaking devices are switched off when faults occur, the fault signal of a certain section of the hydraulic pumps is sent to a DCS electronic control cabinet, and a standby pump can be directly started through a center control system. The grate cooler standby pump interlocking device is suitable for the grate cooler standby pumps.