Non-orthogonal　multiple　access　(NOMA)　is　important　in　5G,　and　the　users　served　in　NOMA　are　often　paired　to　avoid　the　excessive　interference.　However,　for　a　two-user　network,　if　the　channel　condition　of　one　user　is　serious,　this　network　may　require　the　other　user　to　relay　this　user＇s　signals.　In　this　case,　the　demands　of　these　users　are　possibly　different.　Specifically,　the　relay　user　may　want　the　node　to　increase　the　spectral　efficiency　for　compensating　the　cost　of　relay.　On　the　other　hand,　because　privacy　information　may　be　contained　in　signals,　the　indirect　communication　user　may　primarily　focus　on　his　or　her　information　security.　Therefore,　we　propose　a　novel　physical　layer　scheme　to　satisfy　these　demands.　Different　from　the　existing　relay　schemes　in　NOMA,　our　scheme　has　the　following　characteristics:　(i)　through　power　allocation,　the　relay　user　can　extract　his　or　her　signals　with　spectral　efficiency　improvement;　(ii)　through　a　signal-level　method,　the　relay　user　can　forward　the　indirect　communication　user＇s　signals,　but　he　or　she　is　difficult　to　learn　the　privacy　information　in　these　signals;　(iii)　through　a　mechanism,　the　indirect　communication　user　can　attain　his　or　her　privacy　information.　Our　scheme　is　able　to　support　the　relay　user＇s　demand,　and　this　eavesdropping　suppression　in　our　scheme　doe　not　depend　on　the　complicated　encryption　techniques　and　positive　secrecy　rate.