The invention relates to a preparation method of a composite antimicrobial liquid soap, which comprises the following steps: adding 0.2-0.6g of olive leaf extract into water at 22-28 DEG C, stirring uniformly, adding 20-30ml of glycerol, adding deionized water to 70-80ml, heating to 45-50 DEG C, oscillating at constant temperature for 8-12 hours, cooling to 22-28 DEG C, adding 20-30ml of 98-99.7 wt% ethanol and 0.05-0.1g of triclosan, stirring uniformly, and regulating the pH value to 6-8, thereby obtaining the composite antimicrobial liquid soap, wherein the mass content of the olive glycoside in the olive leaf extract is 30-40%. The invention also relates to a composite antimicrobial liquid soap. The composite antimicrobial liquid soap has the advantages of no toxicity, high antimicrobial property, favorable volatility, high stability and skin care.