In pipeline transportation, the measurement results of turbine flowmeter are easily deviated by unsteady flow. In order to guide the selection and correction of turbine flowmeter under pulsating flow condition, it is necessary to estimate the maximum pulsation error of turbine flowmeter under pulsation conditions. Ignoring the change of fluid pressure and temperature, based on dynamic characteristics of turbine flowmeter and conservation of energy, the upper limit formula of sinusoidal pulsating flow error is derived by calculating the work ratio of pulsating flow and steady flow to the impeller in one pulsating period. A CFD simulation model of turbine flowmeter was established based on 6DOF model and UDF. The air flow test platform is built, the working grade standard device is used as the reference, and two flowmeters are connected by a tube section with built-in rectifiers. Compared with the flow value under constant flow, the error limit under each pulsating condition is calculated. The maximum pulsation difference between the results of the formula and CFD simulation is 0.281%, and 0.224% between the results of the formula and the air flow experiments. The upper limit formula for pulsation error is proved its accuracy when compared to the results of CFD simulation and air flow experiment. The pulsation error upper limit formula is proved to be accurate, and can be directly used to estimate and correct the value under the condition that the pulsation frequency is greater than 10 Hz.