Different meteorological conditions lead to different road surface conditions. In order to increase the safety level of driving on the different road conditions on high way, from the view of meteorological conditions, the influences of different road conditions, such as dry, wet, snow and ice on road traffic safety are analyzed. Using the method of the mathematical method, under the condition that the sum of running distance and braking distance is less than the visible distance, the calculation formulas of the maximum speed limits on the different road conditions on the high way are derived based on the safe distance. The dual exponential model is used to evaluate the longitudinal road friction coefficient，and the values of the corresponding safely limited speeds are computed according to different visible distance and road fiction coefficients.