The invention discloses a steel rail damaged connector in-situ welding construction technology. Damaged connectors are mainly processed according to the steps of making preparation for construction, sawing the connectors at low temperature, releasing a steel rail fastener, making the steel rail elongation meet requirements, bending a steel rail, aligning the correctors, thermally processing the connector after welding and finally locking the steel rail. The construction technology is applicable to processing damaged connectors of a newly-built line and an existing line steel rail. Processing time can be shortened, time is saved for intensive later-period welding construction of the steel rail, transporting and rail welding construction staff are reduced, and material consumption of the steel rail and connector welding is reduced. The number of the steel rail connectors is not increased, it is avoided that because the number of the connectors is increased, the risk of the damaged connectors is increased, and the later-period running and maintaining workload is not increased; raw materials of the steel rail are saved, and the damaged connectors can be processed in a more economical and efficient mode.