Abstract: In the process of measuring the hydrogen adsorption characteristics of Palladium Oxide(PdO)getter by constant volume method at room temperature,it is found that the adsorption process will produce gaseous water,which will affect the measurement of the pressure of the adsorption chamber.The accumulation of this error will eventually lead to inaccurate measurement of the hydrogen adsorption performance of PdO.It is found that the LN₂cold well auxiliary adsorption chamber can be used to condense the gas water in the original device,which can eliminate the influence of the gas water on the total pressure measurement.The experimental data before and after LN2 cold well cryocondensation technology is compared and analyzed,which proves that the method can effectively improve the accuracy of PdO hydrogen adsorption performance test.