Abstract: A new process for the application of internal insitu pipeline coating with double-pig is systematically introduced. It is pointed out that the process can be used to coat continuously the inner surface of long pipe with bend, which can deal with the inhomogeneous coating and be easy to apply coating around bends; and the process is reliable in stable operating with homogeneous coating. The accelerated-type epoxy coating material should be used during applying. The applying procedure of this process is critical and limited to the pipe with uniform diameter because of curvature radius of bend. At present, the insitu double-pig applying process is an effective method on inner coating or inner rehabilitation.