Abstract: The calculation methods of internal forces in beams with prestressed anchor-rope on foundation in high slope project are discussed based on Winkler s hypothesis, and the beam on half- space elastic foundation, respectively. These methods are compared with each other in the internal force calculation of an engineering case. According to the analysis of calculation results, the applicable condition for each calculation method is concluded. In addition, the mode of force acting on beam on foundation is analyzed for the pulling and working periods of anchor-ropes. It is pointed out that the internal forces in either the two periods should be calculated respectively. The rational verification methods are also suggested in this paper.