The present invention discloses digital copyright protection method, which includes: stream media server negotiation with copyright center to generate copyright object RO, RO carrying copyright service regulations and establishing encrypted communication channel information; subscriber equipment receiving RO, through said establishing encrypted communication channel information carried by RO to establish encrypted communication channel with stream media server; stream media server transmitting media stream to subscriber equipment. The present invention also discloses DRM system, subscriber equipment and multi-media server.; Through encrypting logical channel rather than encrypting media stream itself, the present invention avoids additional decrypting media stream consumption in application layer of terminal end, reduces terminal equipment performance requirement and meets subscriber's taste. Moreover, through establishing exclusive logical channel between terminal equipment and stream media server, the present invention also reduces risk of intercepting and capturing media stream by third party and raises end-to-end communication security.