In this study, the microwave-induced Co–Mo and Ni–Mo catalysts were combined with a high-dielectric-constant medium to absorb microwave energy and convert it into the heat energy required for syngas production. The microwave conditions were a microwave power of 450 W and a total microwave time of 210 min with the volume ratios CH4/air = 1:2 (partial oxidation) and CH4/CO2 = 2:1 (dry reforming reaction). The results showed that the average yields of H2 and CO were 43 and 35.7% in the partial oxidation reaction with Ni–Mo as catalyst, whereas those in the dry reforming reaction were 44.4 and 24.9%, respectively. On the other hand, with Co–Mo as the catalyst, the average yields of H2 and CO were 50.7 and 35.9% in the partial oxidation reaction, whereas those in the dry reforming reaction were 62.6 and 40.6%, respectively. Owing to the high activity of the Ni–Mo catalyst, it is easier to shield the metal coated on the surface by coke deposition. As the reaction time proceeds, the activity of the Ni–Mo catalyst decreases, and the syngas yield is reduced. Therefore, it is feasible and innovative to combine microwave-induced Ni–Mo and Co–Mo catalysts with a high-dielectric-constant medium to absorb and convert microwave energy into heat energy to produce syngas.