The embodiment of the invention provides a visual positioning method and device, and the method comprises the steps: obtaining a projection image of an RGB three-dimensional point cloud map of an application environment on a camera imaging plane at a first moment; obtaining a camera image of the scene at the second moment; performing image feature matching on the projection image and the camera image to obtain a matching point set of the projection image and the camera image in pixel coordinates; according to the matching point set of the projection image and the camera image in the pixel coordinates, acquiring the pose variation of the camera and combinding the known camera pose at the first moment to obtain the camera pose at the second moment. The method has high precision. Through lowcost and high precision, cost of the visual positioning device is effectively reduced. The camera is used as a sensor. More applications can be developed under the condition that the sensor is not added, and high expansibility is achieved. Finally, due to the high integration level of the existing camera module, the light weight and miniaturization of the positioning device can be realized.