The photomechanical effect (PME), characterized by light-induced mechanical deformation in materials, has gained significant attention across various domains. Photomechanical modeling, integrating photochemistry and mechanical behavior in photoactive materials, is a crucial tool for understanding and optimizing functionality. In this review, we provide an overview of recent developments in mechanical modeling and numerical simulations, focusing on finite element simulations in organic photoactuators. We conducted a systematic literature search from the discovery of the PME, examining progress in modeling diverse organic photoactuators, including polymer-based and liquid crystal elastomer. Integrating light and mechanical constitutive models has enabled the accurate representation of the photomechanical responses of these materials. This review summarizes methods for simulating light-induced deformation, factors influencing photomechanical responses, and current field limitations. Additionally, this review introduces mechanical models as indispensable tools for describing the mechanical behavior of organic photoactuators. In conclusion, developing novel organic photoactuators requires establishing generalized photomechanical couplings to optimize design, enhance light-induced responses, and facilitate cost-effective commercialization. This review serves as a valuable resource for researchers interested in this field, stimulating further exploration of organic photoactuator applications.