The utility model relates to the technical field of oil exploitation, in particular to an oil extraction and water injection device and an oil extraction and water injection pipe assembly. The oil-extraction water-injection device comprises an oil-extraction water-injection pipe assembly and an oil-well pump. The oil extraction and water injection pipe assembly comprises a sleeve and an oil extraction pipe arranged in the sleeve, the sleeve is provided with an oil inlet hole, the oil extraction and water injection pipe assembly further comprises a water injection pipe, the water injection pipeis arranged between the oil extraction pipe and the sleeve in a sleeved mode, a water injection cavity for water flow to pass through is defined by the water injection pipe and the oil extraction pipe, and a water injection opening communicated with the oil inlet hole is formed in the cavity wall. According to the water injection and oil extraction combined device, the water injection pipe is arranged on the outer side of the oil extraction pipe; a water injection cavity is defined by the oil extraction channel and the oil extraction pipe, the oil extraction channel and the water injection channel are separated, a complex flow channel conversion short section in an oil extraction and water injection device in the prior art is replaced, the complex degree of actual operation can be reduced, oil extraction and water injection efficiency is improved, and the device has the advantages of simple structure, reasonable arrangement, low manufacturing cost and the like.