Abstract: From the characteristics ofmass terrain data in a railway location system, a practical fast algorithm for strip digital terrain model (S-DTM) generation was proposed based on the constraint DelaunayTIN (triangulated irregularnetwork). Thismethod takesmany of the characteristics of large strip terrain areas into consideration, such as obtaining the boundary ofsub-areas, finding outpoints at different sides, shortestdistance, characteristic lines, and special areas, etc. The decomposition and structure ofquad-tree are used to large triangulated netmodels constructed to increase the efficiency of the generation and application of S-DTMs. This method has been used in a virtual environmental railway location system. The result of application in several practical railway lines shows the validity and reliability of the proposedmethod to establishing continuous strip digital terrainmodels.