This invention relates to a kind of ozone-catalyst method automobile tail exhaust purifier and the purifier and the purifying technology thereof. The venturi tube of the purifier is connected with the ozone outlet tube of an ozone generator, which has 2-10 pcs of ozone generating-lubes, the ozone generator and the catalyst box are jointed by a fixing plate, and then fixed on the automobile exhaust pipe. The purifying technology includex ozonation of the poisonous components in tail exhaust: CO, HCx, Pb(C2H5), etc. and calalyst oxidation of the low concentrated poisonous substances produced by ozonation, to completely change them into CO2 H2O, NO2 or trace amount of low moleculor organic substances.