The invention discloses a mobile financial 
management system based on a cloud service and a transaction method. By utilizing the existing safest 
USB key identity 
authentication, a 
bank USB key 
chip and a user edition mobile terminal are combined together to form a customized user edition mobile terminal, so that the terminal has a 
USB key identity 
authentication function; USB key identity 
authentication is provided for a user to form 
payment information subjected to USB key identity authentication; then a cloud 
end system and a 
bank system are combined to authenticate the 
payment information subjected to USB key identity authentication so as to fulfill the aim of safe 
payment; and moreover, a safe 
bank USB key 
chip is installed in a customized edition user 
terminal system, and thus, a financial product 
purchasing activity can be completed instantaneously, is not limited to time and space, and is more convenient and rapid. Meanwhile, according to the mobile financial 
management system and the transaction method which are disclosed by the invention, by arranging a merchant edition terminal and a housekeeper edition terminal, information interaction among a bank worker, a user and a merchant is formed, and an effective 
communication channel is provided for three objects.