The invention relates to a sliding and rotation transmission mechanism used in a walk assisting device and the walk assisting device. The transmission mechanism comprises a braking roller, a friction piece and a braking component, wherein the braking roller is connected to the output end of a reducing mechanism of the walk assisting device and can rotate along with the reducing mechanism at the low speed and high torque; the friction piece is arranged on a roller portion of the braking roller; the braking component is installed on a fixing plate which is fixedly connected to a side plate of the walk assisting device, and by means of the friction piece, the rotation of the braking roller can be braked in the radial direction or the axial direction. The transmission mechanism is used in the walk assisting device, the walk assisting safety can be improved, battery consumption can be inhibited, and product miniaturization requirements can be satisfied.