The traffic parameters are the main structure design parameters, including traffic volume、 traffic composition、 standard axial load、 axial-load conversion and growth rate of traffic volume or equivalent axle load action .According to the current heavy characteristic of traffic axial load and current applications of high-grade road asphalt pavement, based on current Asphalt Road Design Standard , combined with the latest research achievements home and abroad and in response to asphalt pavement on semi-rigid base ,traffic axial load is investigated and the axial load characteristic is analyzed firstly using theoretical analysis and experimental research ,by virtue of it, heavy axial load is defined and standard axial load is chosen; axial-load conversion method dependent on asphalt pavement deflection equivalence and tensile stress equivalence of semi-rigid base is significantly studied, as well as axial-load conversion method dependent on rutting equivalence and season correction and temperature correction in axial-load equivalent conversion ; at the same time ,growth rate of equivalent axle load action is researched as well as wheel track lateral distributing rule and the method of transforming the traffic volume observational data into equivalent axle load action.Starting with the widespread axial load investigation and axial load spectrum distribution rule analysis, in the paper the popular trend of vehicle overload ,heavy and large trend of axial load are analyzed and summarized, as well as some axial load characteristics such as most of the vehicle are two-roll and three-roll, most of wheel pressure is above average and the range of axial load distribution is wide ,the average axial load is from 120KN to 30KN and so on. On this basis, according to current traffic axial load situation and road structure load-bearing capacity ,heavy axial load standard of wheel-type(double-wheel with single-axial) is proposed(>120KN~ 130KN),and standard axial load used in heavy axial load traffic asphalt road structure design is suggested based on the equivalent principle of axial load conversion and current study condition (still use BZZ-100 as standard axial load).According to current characteristic of vehicle overload and heavy axial load, taken the limitation of Asphalt Road Design Standard into consideration(the axial-load conversion is only suitable to the axial load smaller than 130KN) ,and based on equivalent principle of axial-load conversion, influential factors to axial-load conversion index n are taken into account with pavement structure design and pavement deflection test and rutting experiment research and three formulae are