The invention relates to a UV photocuring anti-fogging agent and a preparation method thereof, belongs to the chemical technical field, and provides the UV photocuring anti-fogging agent and the preparation method. The UV photocuring anti-fogging agent is prepared from nano particles, a solvent, a modifier, hydrophilic photocuring resin, hydrophilic photocuring monomer, a photoinitiator, a flattening agent and a dispersing agent. The anti-fogging agent prepared by the preparation method does not affect characteristics of a base material, is good in effect of inhibiting fog forming, has relatively high hardness and wear resistance, and provides powerful protection the transparent substrate. Meanwhile, the anti-fogging agent is simple and convenient in operation.