Based　on　the　Fast　Lagrangian　Analysis　of　Continua　(FLAC)　method,　shield　tunnelling　can　be　simulated　by　using　the　gap　model　(GM)　and　the　stress　release　model　(SRM);　each　model　is　proposed　to　be　depicted　using　two　independent　parameters　in　which　the　GM　adopts　ground　loss　(ls),　displacement　offset　(de)　and　the　SRM　adopts　the　average　stress　release　ratio　(Sm),　uneven　stress　release　ratio　(Su).　According　to　the　typical　observed　data,　distribution　characteristics　of　model　parameters　are　analyzed.　Conclusions　are　drawn　as　follows:　1)　For　the　GM,　after　the　comparison　of　the　fitting　results　of　different　de　with　observed　data,　the　proper　magnitude　of　de　lies　in　the　section　of　0.8∼0.9;　2)　Based　on　the　fitting　results　of　224　cases　of　different　stress　release　parameters　and　the　results　of　the　GM,　it　can　be　seen　that　Sm　decreases　at　first　and　then　increases　with　the　increase　of　ratio　of　H/D,　where　H　is　the　tunnel　depth　and　D　is　the　tunnel　diameter;　at　the　same　time,　Su　continually　decreases.　Finally,　under　the　condition　of　the　same　H/D,　the　Sm　steadily　decreases　as　D　increases.　The　results　may　be　helpful　to　estimate　proper　parameters　for　numerical　analysis　of　shield　tunnelling.