Due to the rule of development of cement concrete pavement disease has its own characteristics, the existing theory, difficult to directly guide the preventive maintenance of cement concrete pavement. Systematic analysis of the cement concrete pavement disease in various stages of development and evolution of the typical mechanism, pointing out that cement concrete road surface disease followed by light to heavy ，material damage loss from joint diseases such as non-structural damage to the structural changes in plate fracture. Based on this rule, it puts forward three keys to delay disease conversion in period of the implementation of conservation measures and the timing of repair options. Furthermore use the survey data from Hunan Yi-Chang Expressway, to sort the maintenance of various conservation measures of the cost-effectiveness. Note the timely implementation of preventive conservation measures can greatly increase the conservation benefits and improve the road service life.