Abstract: The article discusses a calculation method for pipeline backfilling load and introduces four methods for calculating pipe top vertical pressure caused by road traffic changing load; Boussinesq point load method, Spangler method, distributing angle method and stacking method based on Newmark integration of Boussinesq equation. And discusses the approximation of pipe top calculation and the value of traffic load impact coefficient when applying Boussinesq theory. Pipe top's changing load of oil & gas pipelines with common diameter is calculated by ways of different methods in light of design load of road culvert. The result calculated shows that Spangler method or. stacking method of Newmark integration can be used to calculate pipe top changing load for common diameter oil & gas pipelines when the cover on the pipe top exceeds 1m. Furthermore, an effective method for controlling the load of buried pipeline is to increase cover depth on road crossing pipeline.