<p>Underground operations in deep coal mines have become frequent with the increasing demand for coal mine resources. The high gas pressure and ground temperature in deep coal seams will increase the frequency and intensity of coal mine dynamic disasters, restricting safe and green production. Therefore, a self-developed gas-bearing coal thermal-fluid–solid coupling triaxial seepage device was used, and uniaxial compression tests with an effective confining pressure of zero were carried out under different gas pressures and temperatures. The coupling mechanism of coal damage and energy under gas pressure and temperature was explored. The results show that gas pressure and temperature deteriorate coal strength. The peak input and elastic energy densities decreased non-linearly, while the peak dissipated energy density increased with the gas pressure and temperature. The fitting curves of peak input and elastic energy densities under different gas pressures and temperatures have a first-order derivative relationship with that of peak dissipated energy density. Gas pressure and temperature can effectively reduce the bursting liability of coal seams, but they provide external excitation conditions for outbursts, which can easily induce compound dynamic disasters of coal. The fractal dimension increases in a cubic function relationship with gas pressure and temperature and has a good positive linear relationship with the proportion of dissipated energy density. A constitutive model for coal damage based on energy dissipation was established by analyzing the damage mechanism of coal under the dual effects of gas and temperature. The model was verified to be reasonable through experimental data.</p>