The invention provides a dynamic intelligent detecting platform and method for motor vehicle external characteristics. A motor vehicle is made to simulate various speed and load changes in actual driving through the detecting platform, all external characteristic indexes such as axle loads, side sliding, high-speed and low-speed braking, power, oil consumption, waste gas exhaust, sealing performance, headlamps, steering lamps, a fog lamp, a marker and contours are fast completed at a time under different road surface butt joint and half-to-half separation conditions, and a chart curve is formed and uploaded to a network to become public data sources for social share. Because the inner source factors of an automobile are not taken into consideration, measurement of an ABS, an EBD, an ESP and a cruise control system becomes possible, a uniform standard for evaluating the motor vehicle external characteristics is enacted and provided for the automobile industry chain, external characteristic detection is provided for the links of research and development, delivery inspection, automobile using detection and maintenance, and a historical breakthrough is made in site, time, mode and management. A standard is provided for the Internet of things, public safety and energy conservation and environmental protection of automobiles worldwide.