Mitigating the massive emissions of greenhouse gases is one of the main measures taken to resolve the current growing climate problems. The electrochemical reduction of carbon dioxide to economically valuable chemical fuels has attracted the intensive attention of scholars. This review provides an overview of the application of conductive diamond in electrocatalytic reduction and outlines the improvement of electrochemical properties by employing metal particles to modify the surface. Meanwhile, the carbon-based electrode materials represented by glassy carbon and diamond-like carbon also have broad research value. Emphasis is placed on the electrochemical properties of boron-doped, transition metal modification, and co-doped diamond film electrodes with appropriate extensions. The carbon-chain compounds produced by the reduction reaction are also briefly described, mainly using formic acid and ethanol as examples, and focusing on the switchable selectivity of the multi-carbon products. In addition, the development directions of electrochemical reduction technology are prospected.