Compared with the single straight tube, the double straight tube shape can reduce the pressure loss and increase the signal of the sensor. The actual structure is shown in the figure. The driver is placed in the center, and the two photoelectric sensors are only symmetrical to the two sides of the center. The measuring tube is less affected by the axial force. When the fluid is not flowing, the photoelectric sensor is subjected to the same phase of the displacement generated by the tube. Coriolis forces are generated when a fluid medium flows through two vibrating measuring tubes. This force causes opposite displacements on either side of the vibration point of the measuring tube. The fluid medium in the measuring tube before the vibration point attenuates the vibration of the tube, that is, the displacement speed of the tube slows down. The fluid medium in the test tube after the vibration point strengthens the vibration, that is, the displacement speed of the tube is accelerated. Through the photoelectric sensor, the phase difference between the two ends is measured. This phase difference is proportional to the mass flow in the measuring tube when the oscillation frequency is constant.