For the low precision of the matching between engine and hydraulic torque-converter

a method of multi-objective optimization is presented.Based on the relevant characteristic curve

the starting performance

power efficiency and fuel economy are taken as the optimization targets when both of the two are working

multi-objective optimization mathematical model of the matching between engine and torque converter is established.Torque converter loop diameter optimal parameter is deduced through the MATLAB.Finally

a numerical example is given and the optimization results are analyzed.