14. The document collaborating method among multiple users, as recited in claim 13 , wherein once the shared document is signed by the designated user, the message account of the designated user automatically sends a notification of signing to the user who distributes the shared document.
13. The document collaborating method among multiple users, as recited in claim 1 , further comprising, when the document is shared, the user who receives the shared document signing the shared document via marking a status of the shared document or a digital signature.