The invention discloses a multi-effect laundry detergent and a preparation method thereof, and relates to the field of chemicals for daily use. A nonionic surfactant, a buffer, dodecyl dimethyl ethylammonium bromide, glycerine, bentonite, diatomite, potassium laurate, alkali protease, amylase and the like are compounded to prepare the multi-effect laundry detergent. The content of the surfactantof the detergent is low, the cost can be saved, preparation steps are simple, the concentration is low, the detergent can be dissolved rapidly, clothes are easy to rinse, the dilution resistance is high, the multi-effect laundry detergent has multiple effects of bacteria resisting, softening, bleaching, high detersive power and the like, and can deeply clean washed objects, any perfumes or brighteners are not added in the formula, the fragrance is natural, the PH value is 7-9, damage to skin is low, waste water emission is low in pollution to the environment.