The emulsified base liquid was prepared by compounding two different surfactants (OP-10 and SDBS) and by using rapeseed oil as the base oil,the effect of preparation process on the stability of emulsion was investigated.Tribological properties of two kinds of thiophosphates additives and T321 added to the emulsified base liquid were studied.The surface morphology of the worn steel ball was analyzed by SEM,and the mechanism of friction and wear was discussed.The results show that the best process for preparing emulsified base liquid at room temperature is that the shear rate is 15 000 r/min,the emulsified time is 10 min,the mass ratio of OP-10 to SDBS is 1∶2,and the mass content of rapeseed oil is 8%.The emulsion after added additives has better antiwear and frictionreducing properties,and the additives can effectively reduce the wear.This is because the additives and T321 containing nitrogen,sulphur and phosphate,and in the process of friction,a boundary lubricating oil film containing N,S,P and other active elements was formed on the surface of the steel ball,which effectively reduces the wear scar diameter and friction coefficient,thus improves the tribological properties of emulsified base liquid.