The structural and chemical parameters of 23 kinds of ionic liquids in dimethyl sulfoxide were calculated by ab initio algorithm and polarization continuum model,and a quantitative structure triboability relationship model with good prediction performance was established.The results show that the molar specific heat capacity and molecular volume of ionic liquids are the main structural and chemical parameters that affect the frictionreducing performance of ionic liquids in dimethyl sulfoxide.The frictionreducing performance of ionic liquid dimethyl sulfoxide system is positively correlated with the specific heat capacity of ionic liquid in dimethyl sulfoxide solvent,and negatively correlated with the molecular volume.Therefore,the larger the specific heat capacity of ionic liquid and the smaller the molecular volume are,the better the frictionreducing performance of lubricating system is.