For a pavement maintenance project, it is always expected that the road segments to be treated or candidate segments are as long as possible to avoid frequent migration of paving equipment. Four indexes, transverse crack, longitudinal crack, rut depth and friction coefficient, are used to found the cluster analysis model. The primary damage mode of the pavement condition is obtained by cluster analysis based on the Matlab statistical toolbox. The result shows that the model in this paper is scientific and simple, and the evaluation result is impersonal and reasonable, which is highly in line with the practice.