Abstract: An incoherent beam combination based high energy nanosecond pulsed fiber laser includes a nanosecond pulsed seed, a fiber splitter, fiber amplifiers, synchronization fibers, a fiber laser combiner and a laser output head. The output fiber of the pulsed seed is fusion spliced to the input fiber of the splitter; the output fibers of the splitter are fusion spliced to the fiber amplifiers separately; synchronization fibers are fusion spliced between the amplifiers and the input fibers of the fiber laser combiner. The nanosecond pulsed seed is split by the fiber splitter and amplified in the later fiber amplifiers; synchronization fibers make sure the optical time-domain synchronization; the fiber laser combiner allows for the incoherent combination of high energy pulsed laser.