The invention relates to an explosion-proof signal isolation circuit and an operating method thereof. The explosion-proof signal isolation circuit is suitable for being connected to a weighing sensorand sending a weighing signal to a signal processing circuit. The explosion-proof signal isolation circuit comprises a sampling capacitor, a first analog switching circuit and a second analog switching circuit, wherein the first analog switching circuit and the second analog switching circuit are controlled by a microprocessor module; a signal output end of the weighing sensor is connected with asignal input end of an analog-to-digital conversion circuit in the signal processing circuit sequentially through the first analog switching circuit and the second analog switching circuit; and the sampling capacitor suitable for temporarily storing the weighing signal is arranged between the first analog switching circuit and the second analog switching circuit. The explosion-proof signal isolation circuit can effectively avoid the attenuation of the weighing signal in the transmitting process.