The invention provides a waterproof soybean adhesive. The waterproof soybean adhesive contains the following raw materials in parts by weight: 30-50 parts of soybean glue, 2-3 parts of accelerator, 5-9 parts of pigment, 25-30 parts of strong flour, 3-8 parts of alcohol and 2-4 parts of sulfuric acid. The soybean adhesive provided by the invention is prepared in the manner of gelling the strong flour and the soybean glue and then adding the pigment and the accelerator. The waterproof soybean adhesive provided by the invention is free from harmful gas emission, not only can greatly reduce the monitoring cost of the harmful materials but also has an obvious promoting effect for the viscosity and waterproof property of the original soybean adhesive.