In engineering design codes and manuals, the design of jacketed pipe is fully given in detail, and the curvature radius of jacketed pipe elbow is stipulated. According to the codes and manuals, jacketed pipes of different nominal diameters match with the corresponding inner and outer pipe elbows of different curvature radii. However, in project operation, it is found that some of the design parameters cannot meet the actual demands. In order to improve the design quality and the construction efficiency of the project, reduce the material cost and the investment and operation cost of the whole project, it is necessary to put forward a more reasonable jacketed pipe design scheme. Based on the characteristics of jacketed pipe, starting with the actual application demands, and after 2D and 3D physical object simulation which is then compared with actual objects on site, an improved design scheme of jacketed pipe is provided in this paper. From the actual results of application of this improved jacketed pipe design scheme on project implementation, it is proven that this improved design scheme is more pragmatic and effective, and also can meet project requirements. This research results could provide a reference for future design of jacketed pipe in sulfur recovery unit.