Efficient electrocatalytic co-reduction of CO2 and NO3− to urea involves simultaneous generation and stabilization of C- and N-coupling intermediates. Herein, we report positive feedback at the interfaces of an AuPd/SnOx catalyst that enables generation and stable co-adsorption of *CO and *NH2OH at low-potential, fostering efficient C-N coupling for urea formation. A combination of in-situ spectroscopic analyses and theoretical calculations show that *CO2 captures electrons by bonding to the AuPd/SnOx interface, leading to positively charged Pd sites, which promote the NO3RR to give the key N-intermediate *NH2OH. The adsorbed *NH2OH provides electron feedback to the catalyst surface, which not only enhances the adsorption of CO2 and promotes the conversion of *CO2 to *CO to accelerate the CO2RR, but also enhances the adsorption strength of the catalyst for *CO. Owing to this positive feedback, the Faraday efficiency and yield of urea reached 21.3 % and 1280.5 μg∙h−1∙mg−1 at −0.2 V (versus the relative hydrogen electrode), surpassing the performance of most previously reported catalysts. This finding provides new insights into catalyst design for advancing C-N coupling systems.