Tangential turbine flowmeter is applied to oilfield cementing engineering, the impeller structure will have a direct impact on the metering effect. In order to improve the measurement accuracy of flowmeter and the reliability of impeller structure, the impeller structure parameters are optimized. Combining response surface with crowd search algorithm, a three factor four level orthogonal test is designed, and the linearity error of flowmeter instrument coefficient K is established by response surface method δ and the quadratic regression model of flowmeter impeller radius, impeller edge thickness and impeller inclination angle. Taking the minimum linearity error as the optimization objective, the impeller structure parameters are optimized based on crowd search algorithm. The optimal parameter combination of impeller structure is obtained. After optimization, the linearity error of instrument coefficient is reduced from 3. 106 0% to 0. 445 2%. The measurement accuracy and stability of cementing mud flowmeter are improved, which provides theoretical support for subsequent optimization design.