In Human-Computer Interaction, multi-material 3D printing is increasingly recognized for its capacity to produce conductive interactive objects. While various fabrication techniques have emerged in this domain, achieving the integration of highly conductive 3D structures within printed objects continues to pose a significant technical hurdle. Our study introduces Intercircuit, a novel integrated technique developed explicitly for fabricating highly conductive interactive objects. This method employs multi-material printing to form unified components along with their embedded structures of lower conductivity, enhancing conductivity through targeted plating. Distinct from traditional multi-material printing and surface conductivity augmentation methods, the Intercircuit method facilitates the creation of complex 3D circuitry while ensuring superior conductivity. Furthermore, this study introduces a supportive design tool aimed at aiding users in crafting conductive frameworks. Moreover, the practical application of this method is further elucidated through a series of case studies.