Stimuli‐responsive nanomedicines represent a pivotal technology for in situ on‐demand drug release and offer multiple advantages over conventional drug delivery systems to combat rheumatoid arthritis (RA). However, the lack of sensitivity to a single‐stimuli source or the inability to synchronize multi‐stimuli responses can easily lead to challenges in achieving precise theranostics of RA. Herein, a homology‐activated ultrasensitive nanomedicines MnO2‐CQ4T‐GOx (MCG NMs) is designed for NIR‐II fluorescence (NIR‐II FL)/MRI imaging‐guided effective “knock‐on” dynamic anti‐RA therapy. Building upon the characteristics of the RA‐microenvironment (acidic pH, redox), the MCG NMs innovatively construct a MnO2‐Mn2+ reaction system, which can normalized activation sites. The ultrasensitive responsive degradation is achieved using the multi‐stimuli processes in the RA‐microenvironment, triggering release of functional small molecules (Mn2+ ions, GOx, and CQ4T‐BSA). The produced Mn2+ can exert Fenton‐like activity to generate highly toxic hydroxyl radical (•OH) from endogenous H2O2, thus providing the effective chemodynamic therapy (CDT). Moreover, the up‐regulation of H2O2 by GOx‐catalysis not only sensitizes the MnO2‐Mn2+ reaction system but also achieves self‐enhancing CDT efficacy. The NIR‐II FL quenching of CQ4T‐BSA in the aggregated state occurs in MCG NMs, which can be rapidly and precisely “turn on” via the MnO2‐Mn2+ reaction system. Meanwhile, the integration of activated Mn2+‐based MRI imaging has successfully developed an activatable dual‐modal imaging. Feedback imaging‐guided precise photodynamic therapy (PDT) of CQ4T‐BSA can achieve efficient “knock‐on” dynamic therapy for RA.This article is protected by copyright. All rights reserved