Aiming　at　providing　communication　services　to　sparsely-populated　areas　and　easing　the　burden　of　the　existing　ground　network,　non-terrestrial　networks　(NTN)　have　been　under　the　exploration　of　3GPP.　In　this　present　research,　a　novel　design　of　the　initial　access　procedure　is　proposed　on　the　premise　that　both　the　satellite　base　station　(SBS)　and　the　terrestrial　base　station　(TBS)　are　capable　of　leveraging　large　antenna　arrays　to　perform　beamforming　at　both　transmission　and　receiving　ends.　In　the　proposed　architecture,　a　group　of　user　equipment　(UE)　can　share　the　same　resource　for　communication　with　other　groups　of　UE　within　the　same　satellite　cell,　in　light　of　the　spatial　orthogonality　this　designed　system　promises.　Analysis　and　simulations　not　only　reveal　that　in　this　architecture,　a　desirable　signal-to-interference-plus-noise　ratio　(SINR)　can　be　obtained　if　a　proper　searching　beam　offset　is　chosen,　but　also　infer　a　99%　preamble　detection　rate　can　be　reached　even　within　a　very　low　SINR　range　in　single　beam　scenario.