The work aims to study the characteristics and application of testing technologies for oxygen content in the headspace of packaging containers, so as to provide basic technical information for the technology development direction in this field. In this paper, principles and characteristics of electrochemical method, zirconia method, fluorescence method and laser method were introduced in detail, and the test methods of oxygen content in the headspace of special samples which could not be tested by the above methods were introduced. Seven gas samples with different oxygen content were tested by direct collection and underwater collection respectively, and the consistency of direct collection and underwater collection was compared and analyzed. The oxygen content of six special samples such as capsule coffee, cup jelly, canned lunch meat, ampoule bottle, penicillin bottle and ointment was measured by underwater gas collection. For the same sample, the maximum error of the test results of both direct collection test and underwater collection test was less than 5%, and the test results were stable. The difference between the two methods was less than 5%. The maximum error of the test results was less than 10% for the special samples of micro headspace gas or non-transparent material, except for the capsule coffee and canned lunch meat with oxygen content less than 1%. It is concluded that the current electrochemical method, zirconia method, fluorescence method and laser method can basically meet the requirements of most sealed container headspace oxygen content detection. For special samples that cannot be tested by conventional means, underwater collection testing is feasible. Direct collection and underwater collection are almost not affected by the oxygen content in the atmospheric environment during the test, which can realize the high sensitivity test of the instrument. The test results of the two methods are basically consistent.