Detection and analysis of volatile organic compounds (VOCs) as pollutants in the atmosphere and liquids are of great significance because of the detrimental effects of VOCs. A polymer-coated graphene micro-tube piping (GMP) structure with a cross-linked and interconnected channel network was synthesized for liquid sensing. By virtue of their unique cross-linked and interconnected channel network configuration, polycrystalline conformation, and the support of a polymer layer, the resistivity of the 3D hollow micro-tubing GMPs was sensitive to strain, ensuring high sensitivity of the liquid sensor (R/R₀ of ~4 × 10³% for pure acetone and R/R₀ of ~105% for 0.01 wt.% acetone solution). Due to the capillary force, the interfaces of the 3D structures can speed up the penetration of solvents into the polymer, thus promote distinct selectivity within seconds and significantly decrease the response time. Owing to their good selectivity, high sensitivity, rapid response and flexibility, and the ease of use of the sensors and the simplicity of the fabrication processes, the GMP/polymer composites should be a good candidate for liquid sensing.