The efficient utilization of energy dissipating from non‐radiative excited‐state decay of fluorophores was only rarely reported. Herein, we demonstrate how to boost the energy generation of non‐radiative decay and use it for cancer theranostics. A novel compound (TFM) was synthesized which possesses a rotor‐like twisted structure, strong absorption in the far red/near‐infrared region, and it shows aggregation‐induced emission (AIE). Molecular dynamics simulations reveal that the TFM aggregate is in an amorphous form consisting of disordered molecules in a loose packing state, which allows efficient intramolecular motions, and consequently elevates energy dissipation from the pathway of thermal deactivation. These intrinsic features enable TFM nanoparticles (NPs) to display a high photothermal conversion efficiency (51.2 %), an excellent photoacoustic (PA) effect, and effective reactive oxygen species (ROS) generation. In vivo evaluation shows that the TFM NPs are excellent candidates for PA imaging‐guided phototherapy.