Catalysts containing different Cr load (5 %∼15 %) supported on SiO2 were prepared using the incipient wetness impregnation method. The influence of Cr load was investigated for the ethane oxidation dehydrogenation with CO2 and the difference between Co, Fe and Cr were compared. The catalytic activity is affected by the load of the Cr/SiO2.Cr‐10 %/SiO2 exhibits best catalytic performance, providing ethane conversion of 30.53 % as well as 98.64 % ethylene selectivity at 650 °C. Excessive load increases the aggregation and grain size of active phase, which goes against catalytic activity. Furthermore, overload increases the crystallization of α‐Cr2O3, which is difficult for reduction and is adverse for catalytic activity. Ethane conversion of Cr, Co and Fe based catalysts is corresponding to redox ability. Cr‐10 %/SiO2(30.53 %) takes the lead and Fe‐10 %/SiO2 is the least active (18.98 %). Co‐10 %/SiO2 is suitable for reforming reaction as its ethylene selectivity is only 19.60 % at 650 °C.