Disclosed is a union coupling device, which relates to a pipeline connecting tool after perforating and damaging nonmetallic pipelines in oilfield production. The union coupling device which comprises two correspondingly arranged portions is characterized in that two assorted pipeline connectors are structured symmetrically, the outer end of each pipeline connector is provided with a press cap, a pipeline hole is disposed in the middle of the press cap, the outer end of a round pipe-shaped packing is locked with the press cap, and the inner wall of the packing is equipped with pipe threads. The utility model is capable of coupling breakages of pipelines without digging up or replacing the pipelines, thereby having the advantages of light workload, small labor intensity, less time and material consumption, low production cost and slight impact on production of an oil-water well. Moreover, the utility model is capable of performing a certain compensation function of expansion and contraction on pipelines.