The invention relates to a microfluidic device for analyzing dissolved gas in insulating oil and a control method. The micro-fluidic device comprises a micro-fluidic
chip and a heating device, the micro-fluidic
chip is provided with an oil sample inlet, a micro-channel area and a gas-liquid separation area, the oil sample inlet is communicated with the micro-channel area, the micro-channel area is communicated with the gas-liquid separation area, a pump cavity used for containing fluid is formed in the micro-channel area, and the heating device is arranged in the pump cavity. The pump cavity is respectively communicated with the oil sample inlet and the gas-liquid separation area, a piezoelectric
brake is arranged in the pump cavity, the piezoelectric
brake is connected with an elastic pump membrane of the pump cavity, and the heating device is used for heating the micro-channel area; the piezoelectric
brake and the heating device are integrated on the micro-fluidic
chip, and the micro-fluidic chip is small in size and high in extraction efficiency.