The invention discloses a biological eco-friendly multifunctional specific laundry detergent and a preparation method thereof. The biological eco-friendly multifunctional specific laundry detergent comprises: by mass, 30 to 50 parts of alkyl polyglucoside, 15 to 20 parts of coconut oil 6501, 5 to 10 parts of alkali protease, 5 to 15 parts of soapberry soap milk, 1 to 5 parts of matrine, 5 to 10 parts of natural soap powder, 5 to 10 parts of cocamidopropylamine oxide, 0.1 to 0.5 parts of disodium ethylenediamine tetraacetate, 5 to 10 parts of auxiliary agents, 0.1 to 0.5 parts of a preservative, 0.5 to 1 part of essence and an appropriate amount of citric acid. The biological eco-friendly multifunctional specific laundry detergent has a pH value of 6.5 to 7.5. The biological eco-friendly multifunctional specific laundry detergent does not contain organic matters of benzenes and phenols damaging a human body, is safe, green and environmentally friendly, does not produce environmental pollution, can remove a plurality of stubborn stains, avoids clothing color fading, keeps clothing soft and bright-colored, has effects of static resistance, mildewing resistance, bacterium resistance and insect prevention, and is suitable for washing of linen fabric, wool fabric, blended fabric, chemical fiber fabric and cotton fabric. The preparation method of the biological eco-friendly multifunctional specific laundry detergent has simple processes, is suitable for industrial production and has wide application prospects.