Vortex flow sensor effective measurement signal after pre-amplification becomes a pulse signal, the pulse transformer output to the secondary instrument, the impact of the elimination of ground current fundamentally is an extremely effective anti-jamming measures. Improve the structure of the resistance of the fluid shape, so that the sensor can receive a better vortex pressure fluctuations, can effectively improve the signal amplitude. But more effective approach is corresponding to the two sides of the package body of piezoelectric crystals occur in the vortex, which uses a differential piezoelectric sensor and a differential amplifier circuit. Way isolation transformer relatively high cost, volume and large, the manufacturing process is not easy to achieve, greatly reducing the utility. Optical isolator limiting anti-jamming measures, can effectively reduce the interference ground current.