NiCoxP @ NiCo-LDH catalysts are prepared by phosphating NiCo nanosheets on NiCo-layered double hydroxide (LDH) with multi-layer heterostructure. The NiCoxP @ NiCo-LDH could undergo electrocatalytic hydrogen evolution from the methanol/water mixture and value-added formate co-production. During the electrocatalytic reactions, the phosphating NiCoxP nanosheets could greatly improve the electron transfer efficiency, and it has a synergistic effect with heterostructures to enhance the electrocatalytic performance. During the hydrogen evolution and methanol oxidation reactions, the potential is only 0.132 and 1.23 V when the current density reaches 10 mA cm−2. Meanwhile, the NiCoxP @ NiCo-LDH symmetric two-electrode electrolyzer has a lower potential of only 1.43 V at a current density of 10 mA cm−2 and the Faraday efficiency of the production of formate and H2 is nearly 100%. The electrocatalysts also display excellent stability during the water/methanol co-electrolysis.