Halide perovskite materials have garnered significant research attention due to their remarkable performance in both photoharvesting photovoltaics and photoemission applications. Recently, self-assembled CsPbBr3 superstructures (SSs) have been demonstrated to be promising lasing materials. In this study, we report the ultrastable two-photon-pumped amplified stimulated emission from a CsPbBr3 SS/Ag hybrid microcavity with a low threshold of 0.8 mJ/cm2 at room temperature. The experimental results combined with numerical simulations show that the CsPbBr3 SS exhibits a significant enhancement in the electromagnetic properties in the hybrid microcavity on Ag film, leading to the uniform spatial temperature distribution under the irradiation of a pulsed laser, which is conducive to facilitate the recrystallization process of the QDs and improve their structural integrity and optical properties. This study provides a new idea for the application of CsPbBr3/Ag hybrid microcavity in photonic devices, demonstrating its potential in efficient optical amplification and upconversion lasers.