In the chemical looping hydrogen generation (CLHG) system, methane acts as an important reducing gas, whereas iron oxide has poor reactivity with methane, resulting in the inefficiency of the system. Thus, the fundamental reaction behavior between methane and iron oxide of great importance. In this paper, applying a high/low-weight hourly space velocity technique, the reaction behavior in a dynamically operated bed system was investigated based on the outlet gas concentration profiles. As the reduction process proceeded, complete oxidation, partial oxidation, and methane decomposition dominated in sequence. The results also validated that the CO/CO2 relative mole fractions followed the equilibrium diagrams of the Fe-C-O system. The reaction behavior in the packed-bed reactor was a combination of thermodynamic limitation and the reaction front movement. This study suggested that the deep reduction CLHG technology is suitable for increasing the conversion of CH4 in the packed-bed system.