The key to research on the notification obligation of risk increasing is to clarify its legal effect. If the obligor performs appropriately, the insurer has the right to increase premiums to maintain the contract or terminate the contract directly, but it should be of sequence. On the contrary, its legal effect has to be refactored by distinguishing whether there is an insurance accident, and whether the increased risk is insurable and should be blamed, and introducing the theory of causality and prorated compensation principle, so as to guide obligors to deal with the notification obligation rationally.