The development of conjugated polymers especially n‐type polymer semiconductors is powered by the design and synthesis of electron‐deficient building blocks. Herein, a strong acceptor building block with di‐metallaaromatic structure was designed and synthesized by connecting two electron‐deficient metallaaromatic units through a π‐conjugated bridge. Then, a double‐monomer polymerization methodology was developed for inserting it into conjugated polymer scaffolds to yield metallopolymers. The isolated well‐defined model oligomers indicated polymer structures. Kinetic studies based on nuclear magnetic resonance and ultraviolet–visible spectroscopies shed light on the polymerization process. Interestingly, the resulted metallopolymers with