The invention belongs to the field of petroleum and natural gas transportation, and particularly relates to a toxic and harmful gas gathering and transportation and protection and leakage monitoring and control method. The method adopts an integrated system which integrates a double-layer pipeline structure with segmented closed annulus, the theory and control logic of emergency shut-off valve interlocking control, industrial communication and control network and interlocking threshold value calculation to realize leakage monitoring, diffusion control and leakage locating. The actual pressureof each closed segment and a theoretical pressure value are compared on a server side, when a pressure difference occurs, the server side determines whether the leakage occurs or not based on a theoretical threshold value, when the leakage occurs, the location of the leakage can be quickly and accurately determined, emergency shut-off valves in front of and on the back of a leaking pipeline are immediately shut down to prevent further leakage of toxic and harmful gases such as natural gas containing hydrogen sulfide in a gathering and transportation pipeline, and the leakage is controlled in aclosed annular space to eliminate the risk of pipeline gathering and transportation safety and environmental protection.