This paper systematically summarizes and evaluates the designing schemes of the west route of South to North Water Transfer Project. Taking Sangbai, Milin-Tieguanmen, Minxian line as main water transfer route, the joint water transfer scheme of three lines at high altitude, middle and high altitude and middle and low altitude is designed as optimal water transfer plan. By applying GIS spatial analysis and programming solver tools to hydraulics calculation, the scheme's technique parameters are calculated and designed in accordance with the principle of self-flowing by gravity, diverting runoff at high altitude source to low altitude destination, homogenizing longitudinal slope of tunnel bottom, building chain reservoir on the upper stream to regulate reservoir capacity, and diverting water jointly through multiple routes. The maximum annual water transfer capacity is 177.74 billion cubic meters. Compared with the Hongqi Canal scheme, we found that the water transfer scheme of Sangbai-Tieguanmen line avoids the shortcomings of the Hongqi Canal scheme, and it has the advantages of short distance, steep longitudinal slope and convenient transportation facility, also avoids the nature reserves and the high-risk regions of geological disaster. The author believe that the multiple routes combined water transfer scheme plan mainly based on the middle low altitude line should be the first choice for the west route of South to North Water Transfer Project.