The development of the Internet finance makes the financial network become increasingly complex. Considering of the characteristics of Internet finance and relationship level, a framework including multitiered Internet financial network with investors, Internet financial intermediaries, traditional financial intermediaries and investees was proposed. Increasing relationship levels in our framework are assumed to reduce transaction costs as well as risk and to have some additional value for the decision-makers. From the perspective of cash flow, the competitive and cooperative relationships between various decision-makers were explicated, as well as their behavior and optimality conditions. We found that the decision-makers compete within a tier and cooperate between ties to optimize the whole Internet financial supernetwork. Under the Internet environment, the various decision makers face greater credit risk and operational risk, credit risk and operational risk brought about by the problem is more outstanding. The relationship level has little effect on investors' decision, but it mainly influences the behavior of Internet financial intermediaries and the traditional financial intermediaries.