Ethane and CO2 can be converted to synthesis (CO and H2) via the dry reforming pathway and formed important industrial raw material ethylene through oxidative dehydrogenation pathway, which are relating to the C−C bond and C−H bond cleavage, respectively. In this study, density functional theory was used to study the activation reaction of ethane C−H bond, C−C bond on Pd atom with CO2 as oxidant. CH3CH3→CH2CH3+H→CH2CH2+2H is the dominant path for dehydrogenation to ethylene. Adding an appropriate amount of H2 can reduce the deep dehydrogenation of ethylene and increase the selectivity. Under the condition of 873 K with Pd atom as catalyst, it is more inclined to ethane/CO2 reforming reaction. The main route for generating CO is CH3CH2+H→CH3+CH3→CH2→CHOH→CHO→CO. H atoms are conducive to the activation of CO2, CO2+H→COOH→CO+OH is the dominant reaction pathway for CO2 activation. The first reaction in the whole system is the first C−H bond cleavage of ethane.