The surface of a U-2.0Nb alloy pre-coated with a Mo layer was successfully modified by pulsed laser in N2 gas, resulting in an N-Mo co-doped layer. Evaluation of this layer at 363 K in a water vapor environment demonstrated its exceptional corrosion resistance for the U-2.0Nb substrate. Analysis using XRD and XPS revealed that the layer comprises uranium nitrides (UN and UO2-xNy) and uranium alloys (U, Nb, Mo), whose chemical stability and distribution are crucial for significantly enhancing corrosion resistance. This study also confirms that high-energy pulsed laser modification induces the sequential formation of reactants, favoring those with higher melting points. This technology shows promise for developing high melting point, ablation-resistant layers and enhancing the corrosion resistance of advanced nuclear fuels like UN/UC/UC1-xNx, thereby broadening the application scope of pulsed laser modifications.