<p>In modern computer numerical control machining, tool path interpolation using finite impulse response (FIR) filtering has been proven to be an effective method for trajectory generation. In these methods, the kinematic characteristics of the reference signal are determined by the time constant of the velocity command signal and the time constant of the FIR filter. However, existing FIR filter-based interpolation methods encounter challenges in effectively adjusting the time constant when processing tool paths with varying feedrate commands. This often leads to increased machining time and, due to the limitations inherent in the filter characteristics, prevents accurate interpolation of circular segments (G02/G03). To address these issues, this paper proposes an adaptive FIR filter-based tool path smoothing interpolation algorithm. The algorithm adaptively adjusts the time constant according to interpolation commands with varying feedrates. By introducing a specially designed circular interpolation strategy, trajectory errors in arc segments are nearly eliminated. In addition, the algorithm performs corner smoothing on the tool path and constrains the corner smoothing error, thereby enabling high-speed and high-precision continuous interpolation. Simulation results verify the feasibility of the proposed algorithm, demonstrating that it significantly shortens machining time while maintaining machining accuracy.</p>