The dynamic optimization of polymer binder burnout processes was evaluated for a 3D cubic ceramic body in different sample porosities and atmospheres. Optimal heating trajectories of the binder removal processes to minimize the burnout time were estimated by the proposed algorithm. The process model can be constructed by the chemical kinetics of the polymer burnout and the mass transport of the volatile gas evolved from polymer burnout inside the ceramic body. A numerical simulation was used to calculate the buildup pressure distribution formed by the volatile gas which affects the generation of the ceramic defects. The results show that the maximum pressure was found at the body center through the binder burnout period. The process needs to be well-controlled to avoid the formation of a large buildup pressure, especially for the samples with small porosities, during the initial binder burnout stages. In addition, the effects of the operating atmospheres and the sample porosities on the optimal heating trajectories were discussed.