At present, China's national economy is vigorously promoting the rapid launch of infrastructure, urban planning and covers because a lot of road construction use, the market is very promising. Because the function and their quality covers have a great impact on public safety, to develop and improve the professional standards covers practical urgency and broader social significance. Carrying capacity is one of the most important functions of the covers. Vehicles on the road trek covers occurrence of alternating load effects, fatigue damage covers should be most severe, and thus covers the assessment of carrying capacity in addition to the choice of static load test, the more dynamic load test should be carried out experimental research tired. Fatigue test covers the use of life contribute to make the identification, and concluded that the use of life in order to ensure safe use provides a basis for the covers. Covers much use in towns, factories and large distribution center and other local materials, the use of different conditions, to determine the appropriate level of use. Not prepared in accordance with the same conditions apply appropriate covers commodities, not only satisfied with the variety of the road, the use of demand workplace, ensure the safety and reliability of the covers in the application process, but also to maximize the rational use of the information, preventing the formation of capital ruined, covers the production and use of lower cost. Ministry of Construction, professional referral existing norms will cast iron covers bearer class is divided into two heavy and light. Learn cast iron manhole covers professional standards, give full consideration to the covers where the road traffic flow, durability needs, saving many elements of the original data and facilitate the production of devices, composite materials covers should be divided into several different use levels to adapt to different conditions road and places. Ratings were based on load covers production, in favor of safe use and reasonable use of the information covers will happen good economic and social benefits.