采用ＩＴＨＡＣ２００２型氮载气熔融法自动快速定氢仪测定铝镁合主中氢。对熔样条件及试样暴露在空气中对氢含量的影响进行了研究。结果指出，试样称量５～５．５ｇ，熔化电流３００ｍＡ左右的条件较为适宜。挤压态试样在空气中暴露与浸泡在丙酮中的氢含量是一致的。用离子探针微分析仪测氢作定性检验，证明本方法测定铝锂合金中氢是可靠的，相对偏差小于５％。 The main hydrargyrum in Al-Mg alloy was determined by the automatic rapid hydrogen analyzer of ITHAC2002 nitrogen carrier gas melting method. The influence of the melting conditions and the sample exposed to the air on the hydrogen content was studied. The results show that the sample weighing 5 ~ 5.5g, the melting current of about 300mA conditions are more appropriate. Extruded samples were exposed to air and immersed in acetone in the hydrogen content is consistent. The ion probe microanalyzer qualitative test for hydrogen, proved that the method of determination of lithium aluminum alloy lithium is reliable, the relative deviation of less than 5%.