The utility model discloses a test device of highway central separator drainage ability, including the connecting pipe, the connecting pipe is connected with simulation rainfall device through first " T " type connecting pipe, installs watering device on simulation rainfall device's the raceway, still include drainage collection device, drainage collection device installs on the transverse drainage pipe of road surface structural layer below, the utility model discloses carry out on -the -spot drainage test, the laboratory limitation has been overcome to the former column structure of not disturbance as far as, make full use of's the characteristics that highway mobility is high adopt building site waterwheel cooperation rainfall devices to simulate artificial rainfall simulation, have broken away from heavy water storage barrel and hydraulic pump, and experimental duration is strong, can carry out rainfall simulation for a long time, simple structure, the component can become the separate unit by the split, convenient to carry, on -site Assembly is convenient, with low costs and repeatedly usable of while, rainfall control range is wide, can be applicable to similar experiment, and the facilitate promotion is used.