During　construction　of　small　interval　shield　tunnel,　the　magnitude　of　the　advanced　tunnel　stresses　changed.　The　magnitude　and　changing　regularity　of　the　advanced　tunnel　segment　secondary　stresses　were　studied　by　field　test　on　a　practical　project.　By　means　of　steel　sting　surface　strain　gages　and　frequency　instrument　readings,　in-situ　monitoring　on　the　circumferential　secondary　stresses　and　the　longitudinal　secondary　stresses　were　carried　out　in　a　small　interval　shield　tunnel　of　Beijing　subway.　Lasted　curves　of　the　circumferential　secondary　stresses　and　the　longitudinal　secondary　stresses　were　given　by　analysis　of　the　measured　data,　and　a　comparative　analysis　on　maximum　secondary　stresses　and　stabilized　secondary　stresses　in　different　monitoring　point　was　made.　The　analysis　results　of　the　measured　data　show　that　the　circumferential　secondary　stresses　is　pressure,　their　magnitude　is　greater　than　those　of　the　longitudinal　secondary　stresses,　and　the　maximum　magnitude　takes　place　in　the　intersection　of　horizontal　diameter　with　circumference　of　the　tunnel.　The　maximum　magnitude　of　all　measured　circumferential　secondary　stresses　is　12.77　MPa　in　this　project　case.　The　results　may　be　applied　to　quantificational　assessment　to　the　interaction　of　small　interval　shield　tunnel　during　construction　and　conducted　as　reference　material　to　design,　construction　and　field　test　of　shield　tunnel.