The invention provides a penetrating and sleeving device for a plastic pipe, and belongs to the technical field of plastic pipe assembling. The penetrating and sleeving device comprises a metal pipeline clamping mechanism and a plastic pipe clamping, penetrating and sleeving mechanism. An upper gear and an upper rack of the plastic pipe clamping, penetrating and sleeving mechanism are engaged, anda lower gear and a lower rack are engaged. A side support lug of an upper pressing finger is hinged to the left side of an upper swinging rod through an upper pressing finger pin shaft. An upper limiting pin is inserted in an upper U-shaped groove in the right side of the upper swinging rod. A side support lug of a lower pressing finger is hinged to the left side of a lower swinging rod through alower pressing finger pin shaft, and a lower limiting pin is inserted in a lower U-shaped groove in the right side of the lower swinging rod. An upper clamping plate and a lower clamping plate of themetal pipeline clamping mechanism are arranged on a clamping bearing base in an up-down sliding manner. An upper thread section of the lead screw and an upper lead screw nut sleeve are in threaded connection, and a lower thread section of the lead screw and a lower lead screw nut sleeve are in threaded connection. By means of the penetrating and sleeving device, the plastic pipe can be automatically arranged on a metal pipeline in a penetrating and sleeving manner, pipe deformation is effectively avoided in the plastic pipe clamping process, and the structure is reasonable.