<p>Thermo-strength, the load capability of materials under elevated temperatures, is a critical metric for evaluating structural integrity in harsh environments. Temperature has a broad effect on the strength of two-dimensional (2D) materials, and the potential mechanisms can be attributed to the thermally activated bond fracture, thermal fluctuations, and thermal-driven defect evolution. Up to now, a general thermo-strength criterion of graphene with vast types of defects and loading states still remains challenging. In this work, we find that the critical bond energy, defined as the potential energy of the fracture bond at the fracture point, is invariant despite the diverse fracture modes for different types of defects under different temperatures and loading states. While initial bond energy without external loading is dependent on the local environment (residual stress caused by defects) and temperature. Then, the energy difference between the critical bond energy and the initial bond energy exhibits a linear decay with temperature. By quantifying the energy balance between the work exerted by the external load on the fracture bond and bond energy difference, a unified thermo-strength criterion is developed that can accurately capture the temperature-related strength of graphene with different types of defects and loading states. This work offers a new insight into the thermo-strength criterion of 2D materials through a fundamental chemical bond energy-based framework.</p>