An innovative approach, active flexible tool‐assisted shear thickening polishing (AFT‐STP), is introduced to overcome the limitations of low efficiency involved in shear thickening polishing (STP) process of concave surface. The principle and characteristics of AFT‐STP were presented, accompanied by the design of a flexible tool structure and the creation of an experimental setup. Comparative experiments were executed to confirm the beneficial polishing performances of AFT‐STP on glass workpieces. Utilizing the Taguchi method, experiments were planned and results were assessed via the signal‐to‐noise (S/N) ratio to optimize process parameters. A variance analysis was then employed to ascertain the relative influence of four key parameters—polishing speed, polishing gap, abrasive particle size, and abrasive concentration on the polishing performance of quartz glass in STP. The results indicate that polishing gap had the most pronounced effect on surface roughness (Sa) at 57.5%, followed by abrasive particle concentration at 21.9% and polishing speed at 15.2%, with abrasive particle size exerting the least impact at 5.4%. Concerning material removal rate (MRR), polishing gap exhibited the most substantial influence at 60.4%, followed by polishing speed at 23.9%, and abrasive particle size at 9%, while abrasive concentration had the least impact at 6.7%. The experimental findings yield valuable insights into the polishing process for concave surface components. Under the optimal parameters, a concave quartz glass workpiece with diameter Ø 20 mm and curvature radius 488 mm was polished, the average surface roughness Sa of the five measuring points on the surface decrease from 142.18±8.63 (Avg. ± Std.) nm to 5.34 ±1.16 nm in 45 mins with MRR 57.3 nm/min and the surface defects of the processing area were completely removed, leaving only minor pits. The results show that the AFT‐STP is an effective method for high quality polishing of concave surfaces.This article is protected by copyright. All rights reserved.