The invention relates to the technical field of power systems, in particular to a mobile protection cabinet and secondary wiring overheat alarming device, which is characterized in that a tuning device, a tuning device reset button, a smoke alarm indicator, a temperature alarm indicator, a power device, a power device reset button and an alarm master reset button are arranged on a shell; and a template is arranged in the shell and is provided with a tuning unit module, an alternating current power supply module, a sensor unit module and an alarm unit module. The device comprises a smoke sensor, a thermistor, a time base integrated circuit, an external alarm sounder and an alarm LED (light-emitting diode) lamp. The device has the beneficial effects that overheat can be found in time, and alarming can be carried out in time, so that accidents are nipped in the bud, and safe operation of a power system can be ensured; the device has the characteristics of easiness in manufacturing, low cost, high practicability and use reliability; and a key function is played on the safe operation of a transformer substation and the whole power system, and appreciable economic benefits are created for companies.