Vibration characteristics of FG-GPL(functionally graded graphene platelets-reinforced) porous thin plates in a thermal environment were investigated. Thermal vibration governing equations of FG-GPL porous thin plates were established based on the material micromechanical model and a refined first-order shear deformation theory in a nonlinear temperature field. Natural frequency was analytically solved using the state space method. Correctness and accuracy of the model were validated. The most suitable material distribution parameters for high-temperature environments were mainly investigated by analyzing the effects of the thermal environment, material distribution pattern, and their combination on frequency. Moreover, the material parameter combination that maximizes the plate frequency for different thermal gradients were provided. It is found that, by increasing porosity on the high-temperature surface and symmetrically adding graphene on both sides of the plate, the plate maintains a high and stable natural frequency.