Metal nanoparticles associated with local surface plasmon (LSP) resonance, i.e. highly confined electric field and large scattering cross-sections (σ), have been widely used to enhance the light-harvesting of solar cells toward high optoelectronic performance. However, the metal nanoparticles embedded into the solar cells suffer from parasitic ohmic loss that subsequently causes the local temperature to rise, which, in turn, reduces the photoelectric conversion efficiency and stability of solar cells. Previous studies on plasmon-enhanced solar cells have rarely considered the negative effects of metal nanoparticles’ ohmic losses and temperature rise on solar cell performance optimization. Therefore, it is of great interest to alleviate the ohmic loss and temperature rise that are critical for high-performance solar cells. Herein, we propose a model to comprehensively study and optimize the performance of plasmon-enhanced perovskite solar cells (PSCs) from simultaneous optical-electrical-thermal aspects. First, the optical simulation results indicated that the geometric tuning of metal nanoparticles can make full use of the plasmonic effect and significantly improve PSCs’ light absorption. The analysis showed that the embedded nanoparticles with optimal geometry in PSC devices can significantly increase the optical absorption by 17% (41%) compared to non-optimal nanostructures (devices without nanoparticles). Then, we explored the influence of the temperature-dependent carrier mobility on PSC performance from the coupled electrical and thermal studies. Our results indicated that the optimization of the geometrical parameters of metal nanoparticles can minimize energy dissipation, thereby redusing the heat loss and then lowering the local cell temperature. Interestingly, PSCs’ electrical properties such as carrier transportation significantly improved. Consequently, the PSC performance improved with increment in the short-circuit current by 23% and the power conversion efficiency by 38%.