The present invention provides an air exhaust or air-and-smoke exhaust pipe for a clean room and a manufacturing method thereof. The air exhaust or air-and-smoke exhaust pipe is a pipe that satisfies FM4922, FM4910, or another equivalent standard and that is used for exhausting nonflammable chemical gas and corrosive vapor or nonflammable chemical gas, corrosive vapor and smoke in fire. The manufacturing method for the air exhaust or air-and-smoke exhaust pipe is: coating an inner part of a pre-manufactured metal pipe with a liquid coating that can be initially dried at normal temperature or low temperature to obtain an inner coating pipe; and baking the inner coating pipe at a temperature not exceeding 250° C. after the coating is initially dried, thus the coating is completely dried to obtain a finished product.