With theoretical analysis of straddle-type monorail vehicle curve-through performance, conception of ’Oriented torque’ withits evaluation criterion used to rate the oriented performance was presented. With the single factor sensitivity analysis and ADAMS virtualsimulation technology, impact factors of oriented torque were found, and based on vehicle design difficulty and optimization efficiency, themost impact factor was selected. Based on the secondary suspension parameters of vehicle and by using the improved genetic algorithm,oriented torque objective function was optimized, and a group of optimal parameters of monorail vehicles were sought.