Based on the principle of damped vibration,the acceleration of spring vibrator is measured by smartphone.The damping coefficient and viscosity coefficient of liquid are calculated by the general solution of dynamic equation of damped vibration.The measured value of viscosity coefficient is compared with the theoretical value ,the relative error is 0.39 percent.The feasibility of this experimental scheme is demonstrated Compared with the traditional scheme,the method based on smartphone is easy to operate and interesting. Meanwhile,it reduces the instrument cost of traditional experimental methods,which has a certain reference significance for online teaching of physical experiments.