Compared with traditional heating, microwave heating has unique advantage and can enhance the chemical reaction. It is a promising technology for catalytic degradation of VOCs gas. Here we prepared a structured catalyst (Mn-Co/SiC) suitable for VOCs degradation under microwave. The catalyst shown excellent stability under microwave heating and microwave empowered the catalyst with good water resistance. Microwave heating exhibits high energy efficiency. Density functional theory is employed to investigate the microwave-enhanced catalytic degradation of VOCs. The theoretical calculation results indicate that the adsorption energy is more negative under microwave electric field, suggesting that microwave electric field is conducive to the activation of benzene. The electrons on the adsorption surface of the catalyst are redistributed to different degrees under the action of different microwave electric fields, thus affecting the activation of adsorbed molecules and chemical reaction process. The local density of states further reveals that electric fields may facilitate the electron transport.