In this letter, a ray tracing (RT) acceleration method based on the total variation norm minimization (TVNM) scheme is presented. RT is a general tool used to analyze wireless communication environments. However, the simulation is time consuming because of the large number of ray calculations. This letter focuses on radio map interpolation as an acceleration approach. For radio map interpolation, we adopt TVNM, which is a representative edge-preserving interpolation method in the field of image processing. We regard the non-line-of-sight and line-of-sight region boundary as the edge of the radio map and use TVNM to achieve accurate interpolation. Furthermore, we consider known position selection to enhance the interpolation accuracy of TVNM. A computational simulation using commercial RT software revealed that the interpolation accuracy of the proposed method was better than those of other radio map interpolation methods and that RT simulation can be accelerated with an acceptable interpolation error.