The interference characteristics of colloidal gas aphrons (CGA) against IR / MMW was studied to further develop the special interference foam, which is a novel multi-band passive interfering technique. The CGA is of strong stability and good fluidity. The experiment results show that CGA has much better interference ability against IR / MMW than ordinary interference foam. The theoretical analysis shows that the CGA have more interfaces and total reflection advantage due to its structural characteristics such as the small radius of bubble and the thick liquid membrane. These advantages are the important basis of CGA’s excellent interference characteristics according to the theoretical analysis. This paper provides a more feasible and effective approach to apply the coating interference foam.