The invention relates to a vehicle position and gesture estimation method based on a traffic sign. The method comprises the following steps that: firstly, through conventional GPS (Global Positioning System) equipment, obtaining the sketchy position of a vehicle, and obtaining an image in front of the vehicle through a monocular camera installed in front of the vehicle; then, detecting the traffic sign in one frame of image, and processing a next frame of image if no traffic signs are detected; after the traffic sign is obtained by detection, extracting four control point coordinates of the traffic sign, obtaining four pre-stored orthogonal control point coordinates of the traffic sign pre-stored in a database through GPS sketchy information, calculating a plane perspective transformation matrix from a traffic sign position to a database orthogonal position in an input image, and carrying out resolving by the matrix to obtain the accurate position and gesture of the vehicle under a traffic sign coordinate system, wherein the four control points correspond one by one. When the vehicle is driven on a road provided with the traffic sign, the position and the gesture of the vehicle under the traffic sign coordinate system can be quickly positioned, and the method has the advantages of being high in instantaneity, low in cost and easy in large-scale promotion.