The invention relates to a device of a catalyst feed pipeline for the polymerization process of a gas phase olefin fluidized bed, and the device can move a catalyst out of the feed pipeline or load the catalyst into the feed pipeline with the pressure, thereby solving the problem of blockage of the catalyst feed pipeline in an on-line manner. The set of the simple device can move the catalyst pipeline out of a polymerization reactor or load the catalyst pipeline into the polymerization reactor with the pressure under the state of introducing inert gas for protection.