<p>In this work, incorporating the impact of grain boundary sliding, a theoretical analytical model has been proposed for assessing fracture toughness at different temperatures of particle reinforced metal matrix composites. The model can achieve prediction of fracture toughness in varying temperature conditions by utilizing the yield strength and Young’s modulus of the metal matrix at room temperature, along with readily accessible material parameters. And the predictions have achieved good consistency with the measurements of five composites obtained from other scholars’ references. Furthermore, based on the established model, the impact of particle volume fraction and particle size on the fracture toughness of composites, as well as their evolution with temperature were studied within the applicable range of the proposed model. This research not only provides an effective and convenient tool for evaluating the fracture toughness of composites serving in different temperature environments, but also lays the foundation for the strengthening and toughening design of composites.</p>