Elbaite is a natural silicate mineral with a spontaneous electric field. In the current study, it was selected as a pyroelectric catalyst to promote hydrogen peroxide (H₂O₂) for dye decomposition due to its pyro-electro-chemical coupling. The behaviors and efficiency of the elbaite/H₂O₂ system in rhodamine B (RhB) degradation were systematically investigated. The results indicate that the optimal effective degradability of RhB reaches 100.0% at 4.0 g/L elbaite, 7.0 mL/L H₂O₂, and pH = 2.0 in the elbaite/H₂O₂ system. The elbaite/H₂O₂ system exhibits high recyclability and stability after recycling three times, reaching 94.5% of the degradation rate. The mechanisms of RhB degradation clarified that the hydroxyl radical (·OH) is the main active specie involved in catalytic degradation in the elbaite/H₂O₂ system. Moreover, not only does elbaite act as a pyroelectric catalyst to activate H₂O₂ in order to generate the primary ·OH for subsequent advanced oxidation reactions, but it also has the role of a dye sorbent. The elbaite/H₂O₂ system shows excellent application potential for the degradation of RhB.