The invention discloses an online combined resource allocation and payment method based on bilateral auction. The method comprises the steps that each buyer (SP) provides quotation information; each seller (MVNO) provides offer information; an auctioneer (the intermediary) calculates a bidding density function and constructs a joint bidding density matrix, and a bidding density sorting vector is obtained through ascending order or descending order arrangement; whether the resources owned by the seller associated with each element completely meet the resources applied by the buyer or not is sequentially judged, and if yes, the corresponding seller and the buyer are taken as a bidding winning mechanism; then, based on the critical minimum bidding density as a reference, a to-be-charged fee qm of each bid winning seller is determined; a to-be-paid fee pn of each bid winning buyer is determined based on the critical maximum bidding density; and finally the buyers and the sellers corresponding to the pn>=qm are selected for matching to realize resource allocation. The method has the advantages that the distribution waiting time can be remarkably shortened, the sum of benefits of three parties is maximized, the convergence speed is high, the complexity is low, and implementation is easy.