The invention provides a pipeline assembly and an air conditioner with the same. The pipeline assembly comprises a first pipeline (10) and a second pipeline (20) which is arranged on the first pipeline (10) in a sleeving mode, and an annular positioning structure (30) which is matched with the first pipeline (10) is disposed on the inner wall of the second pipeline (20). By means of the technical scheme, the problems that deviation is prone to occur during positioning when a large pipe and a small pipe are matched and the product quality cannot be guaranteed in the prior art can be effectively solved.