Abstract: To ensure the safety of heated waxy crude oil pipeline during in-line rehabilitation, allowable exposed length and impending length of the pipe will be respectively determined by using thermal and hydraulic calculation method for buried heated crude pipeline and safety assessment for in-service pressure vessels with defects. In this research, a software package is developed to compute the reasonable exposed length and the impending length of the pipeline in any position and operating condition, combined with its safety and economy in repairing. In addition, with the elastic foundation beam model, safety measures of backfilling with sand compacted are proposed based on the calculation of the pipe bending stress distribution after backfilling and thus reduce additional stress on pipeline after backfilling.