The invention discloses a prepayment consumption management method and system based on block chain, and a storage medium. The method comprises the steps of storing prepaid recharge paid by a customerinto a bank public supervision account; recording prepaid recharge information and consumption information paid by the customer through the block chain distributed account book; according to prepaid recharge money information and consumption information recorded on the block chain distributed account book, paying to a merchant for payment and settlement by a bank public supervision account; and according to the business information of the merchant, returning the prepaid surplus money to the customer based on a preset intelligent contract. According to the invention, the characteristics of non-tampering, traceability and verifiability of the block chain are utilized; the advance payment does not need to be stored in the merchant, the possibility that the merchant in the prepaid consumptionservice rolls the money and runs out of the way is eradicated, the transfer demand and the refund demand of the advance payment client can be guaranteed, the consumption safety of the client is improved, and the method can be widely applied to the field of the prepaid consumption service.