UV Raman, TG-MS (TPO) and nitrogen physisorption characterization were used to characterize deactivated Mo/HZSM-5 catalysts from coupling reaction of methane CO2 autothermal reforming (MCAR) and methane dehydroaromatization (MDA). The results show that MCAR/MDA maintains the Mo-oxo species throughout the process, reducing the maximum C6H6 yield, but extending the reaction life by at least 4 time. As O/CH4 increases, MCAR/MDA changes from oxygen-deficient to oxygen-rich state. For MCAR/MDA under oxygen-deficient condition, O-2 can only delay the accumulation of aromatics. Grown of coke on Bronsted acid eventually leads to complete blockage of the micropores of the catalyst. Slowly deposited graphite coke in MCAR/MDA extended the critical time by nearly 4 times. For MCAR/MDA under oxygen-rich condition, a 70% C6H6 selectivity was maintained throughout the process. After 3700 min of operation, the remaining micropore volume and micropore surface of the deactivated catalyst remained above 1/3. The timely removal of graphite coke at the pore mouth by the MCAR/MDA reaction under oxygen-rich conditions can eliminate the limitation of C6H6 diffusion, thereby effectively preventing the acceleration of the coke deposit micropores which cause the MDA reaction to be rapidly deactivated.