Achieving tough, fatigue-resistant adhesion and high interfacial thermal conductance (ITC) is crucial in various applications such as electronic packaging, soft electronics, and batteries, yet challenging. Herein, inspired by the tendon to bone adhesion, we present a polymer composite fabricated by incorporating interfacial crosslinking of boronic ester into commercially available polybutadiene that bind with fillers and various substrates. We demonstrate that fillers and interfacial crosslinking can enhance adhesion and ITC while also hindering crack propagation, resulting in enhanced fatigue resistance adhesion. Therefore, the fabricated composite exhibits excellent adhesion strength (12.07 MPa), ultra-tough adhesion (5885.85 J m−2), adhesion fatigue threshold (1377.23 J m−2), together with high ITC (118.4 MW m−2 K−1). We also demonstrate that the linear correlation between ITC and the adhesion fatigue threshold surpasses the relationship with adhesion strength and adhesion energy. In addition, the prepared polymer composite shows effective heat dissipation for electronic devices in various working conditions. It is anticipated that our research will stimulate the conceptualization and utilization of a diverse array of composite materials, including high-performance adhesives and polymer composites with high thermal conductivity.