Efficient electrochemical reduction of CO2 and H2O into industrial syngas with tunable CO/H2 ratios, especially integrated with anodic organic synthesis to replace the low‐value oxygen evolution reaction (OER), is highly desirable. Here, integration of controllable partial substitution of zinc (Zn) with amine incorporation into CdS‐amine inorganic‐organic hybrids is used to generate highly efficient electrocatalysts for synthesizing syngas with tunable CO/H2 ratios (0–19.7), which are important feedstocks for the Fischer–Tropsch process. Diethylenetriamine could enhance the adsorption and accelerate the activation of CO2 to form the key intermediate COOH* for CO formation. Zn substitution promoted the hydrogen evolution reaction (HER), leading to tunable CO/H2 ratios. Importantly, syngas and dihydroisoquinoline can be simultaneously synthesized by pairing with anodic semi‐oxidation of tetrahydroisoquinoline in a ZnxCd1−xS‐Amine ∥ Ni2P two‐electrode electrolyzer. Controlled partial substitution of Zn and amine incorporation into ZnxCd1−xS‐Amine inorganic–organic hybrids resulted in highly efficient electrocatalysts for synthesizing syngas with tunable CO/H2 ratios (0–19.7). Syngas and dihydroisoquinoline can be simultaneously produced at a low cell voltage.