In typical CuNWs-based conductors, CuNWs are deposited on or semi-embedded in the surface of substrates, which cannot avoid the oxidation. Here, we report a strategy to fabricate highly conductive and stretchable conductor with enhanced reliability and robustness through fully embedding CuNWs into the surface layer of poly(dimethylsiloxane) (PDMS) and followed with a high-intensity pulsed light technique. The light energy absorbed by the film not only removes the oxides on the surface of nanowires but also enhances the inter-nanowire connection to achieve high conductivity. The fully embedded CuNWs/PDMS structure showed excellent oxidation resistance in high-humidity and high-temperature environments (85 degrees C, 85% RH), and maintained a low sheet resistance when subjected to 30% of strain for 1000 cycles. Stretchable dipole antenna was fabricated using the fully embedded CuNWs/PDMS conductors, which retained its sensitivity to specific radio frequencies even after 500 cycles of the stretching/releasing process. Furthermore, a stretchable conductive heater was demonstrated, verifying the applicability of our fully embedded conductor for wearable electronics. We believe this work might open up new opportunities for the wide range of practical applications of CuNW-based conductors.