The typical blazar S5 0716+714 is very interesting due to its rapid and large-amplitude variability and high duty cycle of microvariability in the optical band. We analyze the observations in the I, R, and V bands obtained with the 1.0m telescope at Weihai observatory of Shandong University from 2011 to 2018. The model of synchrotron radiation from turbulent cells in a jet has been proposed as a mechanism for explaining microvariability seen in blazar light curves. Parameters such as the sizes of turbulent cells, the enhanced particle densities, and the location of the turbulent cells in the jet can be studied using this model. The model predicts a time lag between variations, as observed in different frequency bands. An automatic model fitting method for microvariability is developed, and the fitting results of our multi-frequency microvariability observations support the model. The results show that both the amplitude and duration of flares decomposed from the microvariability light curves conform to the log-normal distribution. The turbulent cell size is within the range of about 5-55au, and the time lags of the microvariability flares between the I-R and R-V bands should be several minutes. The time lags obtained from the turbulence model are consistent with the fitting statistical results, and the time lags of flares are correlated with the time lags of the whole light curve.