<p>Mechanochemically responsive effects show promise in revealing the underlying microscale deformation mechanism of polymeric materials. In this work, we conducted puncture experiments on multiple network elastomeric membranes embedded with ring-opening mechanophores. During the puncture process, fluorescence signals reveal that the region surrounding the indenter tip sustains the dominant stress concentration, and this activated area expands progressively with increasing indentation depth. A mechanochemical constitutive model is developed to couple the fluorescence response and mechanical deformation. The model quantitatively predicts the mechanical and mechanochemical responses. The simulated fluorescence distributions through finite element analysis show agreement with experimental observations, capturing both the spatial extent and intensity evolution of activated zones. This work offers new insights into applying puncture experiments to characterize the mechanical behaviors of soft materials.</p>