The invention provides a photo-cured polyurethane anti-fog film with a controllable soft/hard structure and a preparation method thereof, and belongs to the technical field of polymer materials. The anti-fog film comprises a polyurethane prepolymer with a soft structure, a polyurethane prepolymer with a hard structure, and a crosslinking agent containing a carbon-carbon double bond according to aweight ratio of 100:(5-100):(0.5-5). The provided anti-fog film has a long lasting anti-fog effect, the surface is scratch resistant, the waterproof performance is excellent, the basic material adhesion force is high, the performance and structure can be controlled and adjusted, the cost is low, the technique is matured, and the preparation method is suitable for production.