This invention discloses a car-carried data collection system use in electro-booster turning experiment including a car velocity sensor, a motor current sensor, a steering wheel torque sensor, a steering wheel corner sensor, a supply circuit, a light-coupled isolation circuit, a microprocessor, a communication interface circuit, a RS-232 interface, an interface switch line, a computer and an image head, which can collect data of turning system of cars traveling on the road actually, record the video images of the turning operation behavior of drivers timely, road and weather states and replay the dynamic curves of coherent experiment data by the computer after the test is ended and further to analyze and compute the changed situation of the test phenomenon and data.