Take the left line of a shield interval construction in Tianjin metro Line 3 as the example and with the shield construction control as the research direction, based on the tunneling in test section, analysis on field data monitoring, analysis on computational simulation, selection of shield construction parameters and analysis on actual monitoring data, the paper makes the research on the parameters optimization of tunneling shield machine under complex line conditions(slope changing and small curve radius). With the track monitoring data of the test section as the analysis basis, focus on the main control parameters, the tunneling parameters are selected by theoretical calculation combined with the actual monitoring to demonstrate the parameter applicability. Research results show that the rational tunneling parameters can effectively control the shield machine sinking during the down-traversing building process in the complex line.