Tunable three-dimensional (3D) integrated optical waveguide chips with optical interconnection function are beneficial to expand the application of optical devices in a 3D integrated photonic module. Here, we propose a thermo-optic (TO) tunable interlayer waveguide coupler based on the metal-printing technique. Low-loss fluorinated polycarbonate (AF-Ali-PC MA) and poly (methyl methacrylate-glycidyl methacrylate) [P(MMA-co-GMA)] are synthesized as waveguide core and cladding layer, respectively. The thermal stability and optical adsorption characteristics of AF-Ali-PC MA are analyzed. Optical signal transmission features of the interlayer coupling waveguides are simulated. The optical response properties and fabrication process flows of a dynamic multilayer waveguide chip can be greatly improved by the metal-printing technique. The on-off time of the TO interlayer coupling chip is obtained as 250 µs, and the electrical power consumption is measured as 7.6 mW. To the best of our knowledge, this is the first time that a TO tunable interlayer waveguide coupler is achieved by an efficient metal-printing method, which is suitable for large-scale photonic integrated circuit (PIC) systems and multilayer optical interconnection (OXC) networks.