1. A computer-readable storage medium which stores instructions which, when executed by a computer, enables a distributed multimedia access system applied in a P2P network having a plurality of nodes and a request node, a user located at the request node inputting preference parameters to the P2P network to obtain a peer list that contains some of the plurality of nodes, to: designate some of the nodes in the peer list that are at shorter distances from the request node than the others of the nodes as first node candidates and performs a random walk process on the first node candidates to search the peer list for second node candidates; calculate similarity between the preference parameters of the request node and preference parameters of the first and second node candidates to obtain similarity values; select some of the first and second node candidates that have similarity values smaller than similarity values of the others of the first and second node candidates as buddies for the user located at the request node; and establish and store a buddy list that contains the buddies; wherein the node candidates store objects related to the preference parameters input by users located at the node candidates; wherein when the preference parameters are determined through attributes of the objects input by the user located at the request node, the similarity calculation module lets object (c i ) represent the objects input by the user c i located at the request node and be defined as a vector of weights ({right arrow over (wi)})=(w i k 1 , w i k 2 ,. .. , w i k n ), wherein the weight w i k n represents the user c i 's preference for the objects and is described by keyword k n , the distributed multimedia access system is further enabled to perform the following calculation: w i â¢ k n = ï˜ƒ O i , k n ï˜„ ï˜ƒ O i ï˜„ wherein O i is the set of the objects held by the user c i , O i,kn is a subset of O i containing the objects tagged by the keyword k n .