Hydrogenated carboxyl nitrile rubber ( HXNBR) is a special synthetic rubber. Compared with hydrogenated nitrile butadiene rubber ( HNBR), the introduction of carboxyl groups gives HXNBR more advantages in terms of physical and mechanical strength, and it can meet the high-performance requirements of new-generation rubber products in aerospace, oil drilling and other fields. However, the traditional catalytic hydrogenation technology of organic solutions has problems such as environmental unfriendliness and complex processes, and there is an urgent need to develop more efficient and environmentally friendly hydrogenation processes. Based on a new ruthenium-based catalyst, this study adopted direct catalytic hydrogenation of XNBR latex and successfully achieved the green preparation of HXNBR. The structure of HXNBR was confirmed through characterizations such as Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (¹H-NMR). At the same time, the effects of different hydrogenation conditions, such as hydrogen pressure and catalyst dosage, on the hydrogenation reaction of XNBR emulsion were studied; based on this, the emulsion catalytic hydrogenation process was optimized. Under the conditions of hydrogen pressure of 8 MPa, solid content of latex of 10% , and rotational speed of the stirring paddle of 450 r/ min, when the catalyst dosage is only 0.013% ( mass fraction ), the hydrogenation degree of reaction could reach 95.42% after 7 h. The performance of the self-made HXNBR(ZZ) and the imported product of the same series, Therban?XT VP KA 8889 (commercial rubber HXNBR), was compared and evaluated after mixing and vulcanization processing. The results show that the physical and mechanical properties, heat resistance to air aging and oil resistance of the selfmade HXNBR(ZZ) are comparable to those of the commercial rubber HXNBR, and it can achieve the domestic substitution of hydrogenated carboxylated nitrile butadiene rubber.