The invention discloses a power source temperature alarm device comprising a power source outer shell, indicating lamps, at least one humidity sensor and a condensation sheet; a surface of an inside of the power source outer shell is provided with the condensation sheet, the humidity sensor is arranged between the condensation sheet and the power source outer shell, the humidity sensor is mountedon a surface of the condensation sheet, the humidity sensor is connected with the indicating lamps, the power source outer shell is provided with small holes, the indicating lamps are exposed on an outer surface of the power source outer shell after running through the small holes, the power source outer shell has a cuboid-shaped structure, each face of the power source outer shell is at least provided with one indicating lamp, and the indicating lamps and the humidity sensor are the same in quantity. Via use of the power source temperature alarm device, detection errors are reduced, attentionpaid by users on power source temperature change can be improved via detection of temperature in a power source, that the power source can work at normal temperature all along can be ensured, and service life of the power source can be prolonged.