As important basic chemical materials, benzene, toluene and xylene are currently mainly derived from petroleum cracking. China is rich in coal and less in oil with an overcapacity of coal-based methanol. Therefore, it is necessary to develop coal-based methanol to aromatics (MTA) production technology and to save energy and reduce CO2 emissions. The MTA process flow was divided into four parts, namely methanol aromatization unit, aromatics/non-aromatics separation unit, aromatics separation unit and non-aromatics separation unit. Different physical property methods were selected for each unit according to different materials and operating conditions, namely PRMHV2, UNIFAC, SRK, PENG-NOB. The kinetic parameters were modified, so that the simulation results were basically consistent with the experimental results. On this basis, the MTA process was simulated by Aspen Plus. Sensitivity analysis was used to optimize the reactor, the extractive distillation tower and the toluene purification and rectification tower. Pressure swing rectification and complete thermal coupling rectification were used to carry out energy-saving transformation of the process. At last, the Aspen Energy Analyzer was used to optimize the heat exchange network of the process. The results show that the optimal reaction temperature of the reactor is 470 ℃, the catalyst dosage is 7 000 kg, the optimum extractant dosage of the extractive distillation column is 10 000 kg/h, and the number of trays of the toluene purification and rectification column is 59, the feed position is 29, and the reflux ratio is 3. After the energy-saving renovation, the pressure swing rectification saves 43% of energy and reduces CO2 emission by 227.3 kg/h; the completely thermally coupled rectification saves 56.26% of energy, reduces CO2 emission by 185.5 kg/h. After the optimization of the heat exchange network, the MTA process saves 52.82% of energy, namely 36.34 MW, and reduces 64.40% of CO2 emissions, namely 6 282 kg/h. The final simulated main products are benzene, toluene, xylene with purity of 97.89%, 99.99% and 99.99% respectively, and output of 397.28, 2 772.81 and 5 486.49 kg/h, respectively. The use of chemical process simulation software to optimize the operating conditions and energy-saving transformation of the MTA process provides a reference for the realization of the industrialization of the MTA process, and meets the requirements of energy conservation and emission reduction in China.