1. A method for verifying a branch instruction prediction mechanism of a processor, the method comprising providing and executing a verification program, the verification program comprising at least one branch instruction for verifying the branch instruction prediction mechanism of the processor, wherein the branch instruction determines whether to use a recursive call and to execute the verification program according to a given condition, and the branch instruction is randomly called by the recursive call to generate various test patterns for verifying the branch instruction prediction mechanism; and determining at least one factor, the factor determining a coverage according to a status of the branch instruction prediction mechanism which is verified by the verification program, wherein the condition refers to identifying a relationship between the factor and a target value.