To　explore　the　surface　settlement　law　and　the　instability　and　failure　mechanism　of　excavation　face　during　shield　tunneling　in　sandy　cobble　stratum,　based　on　the　shield　project　of　Tsinghua　Park　tunnel,　a　shield　tunneling　model　test　was　carried　out　in　sandy　cobble　stratum　by　using　the　φ280　mm　model　shield　test　platform.　The　test　results　show　that　the　transverse　surface　settlement　trough　is　distributed　asymmetrically　towards　the　tunnel　axis　in　sandy　cobble　strata,　and　the　greater　the　stratum　loss,　the　more　significant　the　asymmetric　distribution　due　to　the　rotation　of　the　shield　cutter　head.　On　the　other　hand,　the　face　active　instability　and　failure　develops　from　ground　to　surface　with　a　lagging　phenomenon.　Meanwhile,　the　rotation　direction　of　the　cutter　head　has　a　direct　effect　on　the　location　of　the　surface　collapse　pit.　The　center　of　the　collapse　pit　is　located　on　the　side　where　the　tangent　of　the　cutter　head　rotates　vertically　upwards,　which　needs　to　be　paid　attention　to　in　actual　shield　tunnel　engineering.　©　2022,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.