The invention discloses an automobile appearance active virtual detection system and method based on an unrestrained light plane, and aims at solving the problem of automobile appearance active virtual detection based on the unrestrained light plane. The automobile appearance active virtual detection system based on the unrestrained light plane is mainly composed of a cylindrical surface target (1), a video camera (2), a video camera support (3), a two-dimensional target plate (4), a laser connector (5) and a laser device (6). The automobile appearance active virtual detection method based onthe unrestrained light plane comprises three steps of collecting images, reconstructing a laser plane under a coordinate of the two-dimensional target plate (4), and reconstructing vehicle surface feature points; the automobile appearance active virtual detection system and method based on the unrestrained light plane with simple structure and reliable performance is provided.