The invention discloses an acid and alkali free quick regeneration method for waste oil, which comprises the steps of: flocculation, namely adding the waste oil into a reaction kettle, adding activated clay which accounts for 0.5 to 2 percent of the weight of the oil and cationic-type polyacrylamide which accounts for 0.1 to 1 percent of the weight of the oil into the oil, stirring the mixture for 10 to 30 minutes, standing and precipitating the mixture for 60 to 180 minutes, and removing oxidation residue and a precipitate from the bottom of the reaction kettle; decolorization, namely addingthe activated clay which accounts for 3 to 12 percent of the weight of the oil into the flocculated oil in the reaction kettle, and stirring the mixture for 10 to 30 minutes; and filtration, namely pumping the decolorized oil into a filter for filtration to obtain regenerated product oil. The acid and alkali free quick regeneration method for the waste oil has the advantages that: 1, acid and alkali do not need to be added when the waste oil is regenerated; 2, the regeneration of the waste oil has short time and only needs 1 to 6 hours; 3, the regeneration of the waste oil has low cost, and one ton of the regenerated product oil only needs 180 to 250 yuan; 4, the regenerated oil has good quality; and 5, the regeneration of the waste oil has good working environment and low power consumption, and has promotion value.