Automatic expansion type external pipe packer

The utility model relates to an automatic expansion type external pipe packer which consists of a collar, a main body, an upper limiting sleeve, a lower limiting sleeve, an upper fixing nail, a lower fixing nail and sealing sleeves. The upper end of the main body is connected with the collar by threads. One or a plurality of sealing sleeves are sleeved or sulphurized on the outside of the main body. The upper limiting sleeve and the lower limiting sleeve are respectively arranged at the upper and lower ends of the sealing sleeve, and fixed with the main body respectively by the upper fixing nail and the lower fixing nail. The utility model has the advantages of novel design, simple structure, convenient use and safe and reliable operation; as the method of not using the hydraulic tool to push and also not arranging the liquid pressure transferring through hole on the pipe body is adopted, the utility model can avoid the accidents of adhesive cylinder breakage or hydraulic seal failure, inside and outside communication of the pipe, and the like, effectively enhance the success rate of sealing, and ensure the well drilling construction operation to smoothly carry out.