The work aims to study the surface modification and friction properties of magnesium silicate hydroxide powder as the lubricant additive, so as to improve the film forming performance of magnesium silicate hydroxide powder on the worn surface of equipment, reduce the wear and prolong the service life. The phase transformation process of magnesium silicate hydroxide powder was analyzed by SDT Q600. The magnesium silicate hydroxide powder was modified by different surface modifiers. The effect of different concentration and heat treatment temperature on friction and wear properties of magnesium silicate hydroxide was studied by MG-2000 high speed and high temperature friction and wear tester. Magnesium silicate hydroxide desorbed the adsorbed water from room temperature to 500 ℃, desorbed interlayer water and structural water from 500~800 ℃ and then formed new phase forsterite. Crystal structure was reconstructed between 800~860 ℃, and forsterite- diopside phase transition occurred between 860~1100 ℃. After surface modification with oleic acid, long organic chains were introduced into the surface of magnesium silicate hydroxide powder. The modification effect of surface modifiers was: oleic acid>Sipan 80>stearic acid>Tween 80>KH270>KH560. The dynamic balance of wear and self-repair could be easily achieved in a short time when the powder mass fraction was 10%, and good anti-wear and anti-friction effect could be achieved. Activity, dispersibility and film-forming properties could be effectively improved after heat treatment at 200 ℃ and 400 ℃. Oleic acid can effectively improve the dispersibility of magnesium silicate hydroxide powder in lubricating oil. Heat treatment at 200 ℃ and 400 ℃ can effectively improve the dispersibility and film-forming properties of magnesium silicate hydroxide powder in lubricating oil.