Abstract: A fiber system was constructed to trigger photoconductive semiconductor switch(PCSS) at MHz operation frequency. The fibers in fiber system are arranged in alveolate position and each group has different lengths to make stable time delay. This paper focuses on the calculation of fiber system, group division and program design. Calculation program approves: With the increases of ratio of division radius to beam radius, the efficiency of fiber splitter increases until it reaches a certain point. With stable beam diameter the efficiency of fiber splitter decreases with the increasing of number of plies of fiber; With the stable of radical of fiber system, the maximum variance in the energy contained in each pulse of laser decreases versus the increasing of number of plies of fiber. Experiment has proved that the 10 MHz fiber splitter in output 4 laser pulse bursts and the maximum variance in the energy contained in each pulse is 6.80% while the efficiency of system is 38.07%.