The invention discloses a large-scale rotating machine bearing temperature alarming and monitoring device which comprises an alternating current power source, a fuse, an alarm light, a transformer, a rectifier, a first voltage stabilizer, a second voltage stabilizer, a voice frequency integrated chip, a temperature sensor, a first diode, a second diode, a light emitting diode, a first triode, a second triode, a third triode, an operational amplifier, a loudspeaker, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor and a seventh resistor. The large-scale rotating machine bearing temperature alarming and monitoring device is simple in circuit structure, few in adopted elements, small in size, low in manufacturing cost and easy to manufacture, has voice monitoring and alarming and flicker alarming functions at the same time, is high in caution effect, and easily draws attention of a worker.