This paper presents an algorithm for estimating road surface adhesion coefficient at different slip rates. First, estimation method of slip ratio and utilization adhesion coefficient are proposed. An estimation method for road surface adhesion coefficient is proposed for different slip ratio stages. At high slip ratio, estimates are made by utilization adhesion coefficient. At low slip rate, estimates are made by Bayes' theorem and slope method. Finally, through experimental verification, the algorithm can accurately and quickly estimate the adhesion coefficient of the current road surface.