To improve the performance of the vortex flowmeter, a vortex signal model based Kalman filter of the vortex signal processing method is proposed. According to the characteristics of the vortex signal, a linear vortex signal model is designed. Combining the fuzzy search and iterative algorithm, the Kalman filter algorithm is improved by analyzing the principle and key parameters of the Kalman filter algorithm. The proposed method is verified by simulation and real flow experiments and compared with other methods; the experimental results show that the proposed method has the advantages of adaptive filtering, better anti-interference ability, and faster filtering speed.