A hose take-up apparatus, which includes a flat casing defining a flat receiving chamber having a relatively narrower middle portion and relatively broader upper and lower portions, a twin line welding hose received in the receiving chamber inside the casing, the twin line welding hose having a fixed input end fixedly secured to the back side wall of the casing and connected to the gas supply tubes of the gas cylinders of a welding apparatus outside the casing and a free output end extended out of an outlet at the front side wall of the casing and connected to a welding torch, two guide members mounted in the outlet inside the casing for guiding the twin line welding hose in and out of the casing, and a winding mechanism mounted inside the casing to automatically take up the twin line welding hose.