The main objectives of this work are to experimentally examine the enhancing mass transfer performance of FeO nanofluid on the bubble absorption and to find the optimal method to design highly effective compact absorber for NH3/H2O absorption refrigerator. Based on the microcosmic analysis of the factors affecting the stable performance of nanofluid, FeO nanofluid was prepared by using the ultrasonic dispersion method. The ammonia bubble absorption experiments with FeO nanofluid were carried out and the data of absorption height were acquired. The results showed that FeO nanofluid had an enhancing effect on mass transfer performance, and the absorption height was 2mm higher than that of the water based solution in 2 minutes of the experiment conditions. The curves of the solution temperature in absorption were also given. According to the data of the absorption height and the solution temperature, it is pointed out that there are two factors which might have negative influences on the mass transfer enhancing process.