The invention discloses a vehicle-mounted pavement three-dimensional reconstruction system based on a projection grating, and aims to solve the problem of pavement three-dimensional reconstruction by means of a projection grating. The vehicle-mounted pavement three-dimensional reconstruction system based on a projection grating mainly comprises a bottom plate (1), an F-shaped connection plate (2), a video camera (3) and a projector (4). The vehicle-mounted pavement three-dimensional reconstruction system based on the projection grating has the advantages of small occupied space, simple structure, high detection precision, simple operation, easy installation, low cost and reliable performance.