Pipe fitting and method for blocking pipeline

The invention discloses a pipe fitting and method for blocking a pipeline. The pipeline has an outer diameter of 50 mm or less, and the pipe fitting comprises a split type body, a split type isolationsleeve and a first blocking member. The split type isolation sleeve includes a first tube body and a second tube body, and the first tube body and the second tube body are combined to form a cavity which can accommodate the pipeline to be blocked. The split type body includes a first body and a second body, wherein the first body is provided with a first groove opened at both ends and a first through hole with one end opened and the other end closed, and the open end of the first through hole communicates with the first groove. The second body is provided with a second groove opened at both ends and a second through hole opened at both ends, and one end of the second through hole communicates with the second groove. The first blocking member is used for blocking the other end of the second through hole. The shape