Bentonite grease composition and preparation method thereof

The invention provides a bentonite grease composition including by mass percent, 75%-90% of lube base oil, 1%-10% of organic modified bentonite, 1%-5% of a structure modifier, 1%-10% of an additive, wherein the lube base oil is polyester obtained by a polycondensation reaction of neopentyl glycol and sebacic acid and end blocking by isooctyl alcohol. The bentonite grease composition using the polyester as the lube base oil, due to an unique chemical structure thereof, has a good low temperature performance, and has good sensibility to the organic modified bentonite, so that the bentonite grease has a good lubricating performance, at the same time the condensation point is low, at the temperature of lower than or equal to -40 DEG C a starting torque and a running torque are smaller, the low temperature performance is good, the comprehensive performance is high, and the lube base oil facilitates lubrication of mechanical parts of water pumps, wheel hubs, bearings and the like by the bentonite grease in the harsh environment. The invention also provides a preparation method of the bentonite grease composition.