The stable FeO nanofluid was first prepared in this work. The ammonia bubble absorption experiments about FeO nanofluid-based solution and water-based solution were carried out and compared under the two different conditions of constant flow flux and constant inlet pressure of ammonia gas, respectively. The results show that the absorption effect of ammonia is enhanced by the prepared nanofluid. Under the condition of constant inlet pressure of ammonia gas, the absorption enhanced effect occurs from the beginning of the absorption process; Under constant flow rate of ammonia gas, the enhanced absorption effect is just exhibited in a few minutes from the start. The possible reasons for the experimental results was analyzed and discussed. A reference is provided for subsequent mechanism research on the heat and mass transfer for nanofluids.