The invention belongs to the technical field of preparation of hot melt adhesives, and particularly relates to a high-strength quick-curing bio-based hot melt adhesive and a preparation method thereof. The preparation method comprises the following steps: preparing a dimer acid polymer from dimer acid, sebacic acid, polyether amine, ethylenediamine, an antioxidant and a catalyst, and mixing the dimer acid polymer with a beta nucleating agent toughened polypropylene/SiO2 nano-composite and an organic borosiloxane polymer to obtain the high-strength quick-curing bio-based hot melt adhesive. The prepared hot melt adhesive has good mechanical property, viscosity and self-healing property.