The invention belongs to environment-friendly glue for construction, and particularly relates to environment-friendly nail-free glue for construction and a preparation method thereof. The nail-free glue comprises the following compositions: 12.0-40.0% of polyvinyl acetate resin, 18.0-40.0% of reinforcing filler, 15.0-40.0% of a solvent, 0.5-8.0% of a thixotropic agent, 0.1-3.5% of a coupling agent, 0.1-5.0% of a plasticizer, and 0.1-0.5% of a dispersing agent. The preparation method comprises the following steps: adding the solvent into a homogenizer, starting the homogenizer, then adding the polyvinyl acetate resin, stirring for 1-3 hours until all the materials are dissolved into a transparent and uniform liquid, further, adding the plasticizer, the coupling agent and the dispersing agent, uniformly stirring, then slowly adding the reinforcing filler, uniformly stirring to prepare a flowing pulpy mixture, then adding the thixotropic agent, and uniformly stirring to prepare the environment-friendly nail-free glue for construction. According to the invention, the environment is protected, the construction is convenient, no nail-holes are bonded, the bonding strength is high, and the ageing resistance is excellent.