Engineering of a composite electrode containing Si-based anode materials is important for the practical applications of Si-based lithium-ion batteries. In this work, a hybrid composite anode of silicon/carbon/polymer was fabricated in situ by optimized heat treatment of the coating slurry containing silicon power and polyamic acid polymer, without adding any carbon agent. The resulting electrode has a three-component (silicon-carbon-polyamide) composite structure, wherein the nanohybrid carbon/polyamide matrix is in-situ generated from polyamic acid by optimized heat treatment. The hybrid Si composite electrode exhibits robust binding and conductive properties, and delivers promising battery performance even for high contents of the micron-sized Si powder (similar to 95 wt%). Consequently, the proposed method for Si anode engineering is another effective way to manufacture advanced lithium-ion batteries.