The invention discloses a method for preparing a visible light self-repairing waterborne polyurethane coating material with double selenium bonds on a main chain. The method comprises the following steps: firstly, preparing an isocyanate end capped polyurethane prepolymer with double selenium bonds on a main chain from raw materials of diisocyanate, dihydroxyethyl diselenide, macromolecule dihydric alcohol and dimethylolpropionic acid; secondly, adding triethylamine for neutralization, further adding a proper amount of deionized water for rapid emulsification, slowly adding a diamine chain extender which is diluted with water, and performing emulsification chain expansion under a condition that the rotation speed is greater than 1200r/min, thereby obtaining the visible light self-repairing waterborne polyurethane coating material with the double selenium bonds on the main chain. On the basis of the visible light reversibility characteristic of double-selenium dynamic covalent bonds, the waterborne polyurethane coating material with the double selenium bonds on the main chain is capable of achieving self-repairing of cracks and broken parts under radiation of gentle visible illumination, so that the service life of the material can be greatly prolonged, the potential safety hazard in use can be reduced, and a relatively long service life can be achieved for the waterborne polyurethane coating material. The waterborne polyurethane coating material with double selenium bonds on the main chain is applicable to coating of leather, textiles, paper, furniture, wall surfaces and the like, and has wide application prospects.