A pipe shell evaporator of dual systems of a central air conditioner comprises an outer shell, a copper pipe, a front end cover, a rear end cover and spoilers. The outer shell is a cylindrical shell and is provided with a water inlet, a water outlet, an exhaust hole and a drainage hole. The inner wall face of the copper pipe is smooth, and the outer wall face of the copper pipe is a threaded face.A transverse baffle is arranged in the middle of the inner side of the front end cover. The outer circumference of the rear end cover is mounted and blocked at the rear end of the outer shell throughbolts, and a gasket is arranged between the rear end cover and the outer shell. Each spoiler is a gap exceeding a semicircle, and according to the arrangement manner, part of the spoilers are arranged along the interior of the outer shell at even distances. The outer shell of the pipe shell evaporator occupies all the space of the whole evaporator, and therefore the water inlet and the water outlet of water and media are pre-formed in the outer shell, a large amount of space can be saved, and design of a host is optimized; the water inlet and the water outlet are in flange connection and areconvenient to mount and easy to maintain; and the use frequency of the exhaust hole and the drainage hole is not high, the fault rate is low, and therefore leakage can be reduced by adopting a weldingmethod.