The invention discloses a drainage device for emergency disposal in case of leakage of exposed oil and gas pipelines, and a leakage disposal method thereof, and belongs to the technical field of emergency maintenance for oil pipelines. The drainage device can be used for quick disposal to leakage points on the oil and gas pipelines, and can also gain time for follow-up implementation of permanent repair. When the method is used, once leakage points on the gas pipelines are found, the drainage device provided by the invention can be used for quickly guiding leaked oil gas at the leakage points of the gas pipelines to far ends, and then when a rescue person uses a rigid iron base material to conduct permanent blocking and repairing on the leakage points of the gas pipelines, as the leaked oil gas at the leakage points of the gas pipelines is guided for a distance, the operation safety of the rescue personnel can be improved.