Abstract: It possesses profound practical significance to study the thermal calculation of heated crude oil pipeline at starting both for determining starting time of delivering crude oil and ensuring safe operation of pipeline. In the light of the medium, pipeline, coatings and semi-infinite soil and their unstable heat transmission, a mathematical model for thermal calculations considering temperature dependent relative physical properties of soil is setup. By conformal transformation and cassette integration, the semi-infinite soil region is transferred into a definite rectangle region, this model can be used to do a series of numerical calculations by generalized damping Newton-Raphson method. The method derived is proved feasible by a practical example.