We conduct numerical investigations on turbulent Rayleigh–Bénard (RB) convection modulated by oscillating filaments, where an array of active filaments is adhered to the bottom surface. Our study focuses on the dependence of global heat transfer, quantified by the Nusselt number (Nu), on the rigidity (B) of the active filaments under various oscillation frequencies (ω). We reveal two critical filament rigidities, Bc1 and Bc2, delineating distinct heat transfer regimes: (I) Soft regime (B<Bc1), where negligibly small filament rigidity allows for obvious bending, and Nu decreases with increasing rigidity B in this regime. (II) Elastic bending regime (Bc1<B<Bc2), where elastic bending of filament takes place, inducing swaying motion near the filament root and subsequently perturbing the boundary layers to favor thermal plumes emission. In this regime, Nu noticeably increases with rising rigidity. (III) Stiff regime (B>Bc2), characterized by minimal deformation induced by filament–fluid interaction and the saturation of heat transfer enhancement. Furthermore, we analyze the competition between bending and inertial forces experienced by the filaments through comparing their relative magnitude, from which we theoretically determine both critical rigidities Bc. Our study offers valuable insights into the intricate dynamics of active filaments in turbulent convection, advancing our understanding of heat transfer modulation in active environments with dynamically driving agents. •Mechanism of heat transfer modulation by active filament has been elucidated.•Three heat transfer regimes are identified depending on filament rigidity.•Critical filament rigidity is determined by the competition between bending and inertial forces.