Abstract Research purposes: With the services of lines 1，2，3 and 9 of Tianjin metro，the demand of the passenger for transferring line among radiate lines is increasing rapidly． Based on the Tianjin Overall Planning and Tianjin Urban Rail Transit Network Planing，the study was done on the design plan for the metro loop line around the middle ring area in Tianjin to effectively connect the loop lines with the radiate lines and provide the reference to the similar works． Research conclusions: From the analysis of comparing the combined loop line of the lines 5 and 6 with the combined loop line of the lines 6 and 7，it can be seen the main distributive areas of the passenger flow can be connected by the combined loop line of the lines 5 and 6． In this way，the accessibility between the loop line and the lines 1，2，3 and 9 is improved． So the combined loop line of the lines 5 and 6 is feasible in technology． In the similar works in future，the same construction standard and the same construction schedule should have for the two combined loop lines or above． In order to realize the maximum function of the loop line，the hubs of the passenger flow should be connected by the loop lines based on considering the passenger flow，transfer area and metro vehicle depot．
Cheng Liangkui，Li Xiangfan ． The Principles，Design and Application of the Geotechnical Anchorage，Soil Nail and the Shotcrete［M］． Beijing: China Architecture ＆ Building Press，2008．
2013, Vol. 30 
