Regeneration method for waste lubricating oil

This invention discloses a regeneration mehod for waste lubricant including: settlementing waste lubricant naturally to remove water and mechanical impurities in it, when the content of mechanical impurities is lower than 0.08wt% or pentane undissolved substance is less than 0.30wt%, it is often decompressed and distilled directly, otherwise, a thinner 0-3.5 times of the total weight of the waste lubricant is added to be separated under 30-95deg.C then decompression and distillation are done to it later, then short time distillation and refining to the lubricant is carried out to get regenerated lubricant.