The present invention provides a transmission roller, a pin-teeth cycloid reducer with the same and a bearing. The transmission roller comprises a hollow roller which is made by spirally and closely winding a steel strip or a steel wire, and the length of the hollow roller remains unchanged when both ends thereof distributed along the axial direction are squeezed. When the hollow roller is subjected to external pressure, the ends thereof will not be easily damaged, and will not extend to the middle part during use, thus having a long service life.