The invention relates to a flux test method for a GPU FFMA instruction in a dual-emitting mode. The flux test method comprises the following steps: testing the delay and the flux of a GPU instruction to acquire the delay period and the flux of the GUP instruction; selecting a register operand free of bank collision according to the fact that whether bank collision exists between registers or not; and analyzing and testing the meaning of a control code in the GPU instruction according to the delay period and the flux of the GPU instruction, controlling to start a corresponding emitting mode and thread scheduling of a GPU according to the meaning of the control code, and if the started emitting mode is the dual-emitting mode, calculating and testing the flux of a GPU float-point multiply-add instruction in the dual-emitting mode according to the dual-emitting mode and the register operand. Parameters of the GPU and the corresponding relationship between the parameters and the performance of the GPU are tested through a micro benchmark test program to obtain the relationship between the parameters and the performance, and application to the GPU is favorably optimized.