Processing circuit and signal processing method of sampling circuit

The invention provides a signal processing method suitable for reading a sensing voltage of a processing circuit of an X-ray sensor and a sampling circuit. The processing circuit comprises an amplifier and a sampling circuit. The amplifier includes an inverting input terminal, a non-inverting input terminal, and an output terminal. The inverting input terminal of the amplifier is coupled to the X-ray sensor. The sampling circuit is coupled to the output terminal of the amplifier. The sampling circuit acquires a first voltage, a second voltage and a sampling voltage of the X-ray sensor in different periods. The sampling voltage is between the first voltage and the second voltage. The sampling circuit subtracts the second voltage from the sampling voltage during a readout period to obtain a third voltage, subtracts the first voltage from the second voltage to obtain a fourth voltage, and divides the third voltage by the fourth voltage to read out a sensing voltage of the X-ray sensor. 本公开提供一种适于读取X光传感器的处理电路的感测电压