Abstract: The calculation of the unstable temperature of the soil around pipeline is the first step to evaluate the hot oil pipeline. This paper deals with the ordinary form of pipeline, using two-dimensional unstable heat transmission equations to describe the heat transfer process and build the temperature calculation mode. The effects of the parameters, such as ground surface temperature and pipe diameter etc,are concerned in boundary conditions. The finite difference approach is used to resolve the equations and the thermal parameters of hot
oil pipeline can be got from it. The calculation of a practical examples indicates that the method and codes in this paper meet the needs of actual uses.

Key words: Oil pipeline, Thermal calculation, Temperature distribution, Numerical analysis, Finite difference method