The invention discloses a block chain payment system-based cross-border payment settlement method. According to the method, multiple financial service mechanisms are provided; the method is based on ablock chain technology; an industrial block chain indicates that multiple pre-selected nodes in a certain group are appointed as bookkeepers; the generation of each block is decided by all the pre-selected nodes; and other access nodes can participate in transactions and do not concern the bookkeeping process. According to the method, the problem that settlement exchange rates of different financial mechanisms in cross-border transactions are different so that settlement is not always carried out according to real-time international exchange rates is solved through establishing an exchange rate priority list. According to the method, the problem that transactions fail as different financial mechanism do not always strictly carry out exchange according to international exchange rates and the exchange rates of initiators and receivers are different during the transactions is solved.