The invention provides a multimode fiber beam splitter and a production method thereof. The multimode fiber beam splitter comprises an input optical fiber and multiple output optical fibers, wherein the input optical fiber and the multiple output optical fibers are fixedly connected, the input optical fiber is a multimode fiber, and the output optical fibers are single-mode fibers. According to the multimode fiber beam splitter, the optical fiber at an input end is the multimode fiber, so that laser with higher power strength, larger M<2> factor and larger waist diameter is coupled into the optical fiber at the input end conveniently, and higher input-end laser coupling efficiency is realized; the optical fibers at an output end are single-mode fibers, so that output laser with small divergence angle, small waist diameter and uniform power distribution can be obtained. Further, in the production method of the multimode fiber beam splitter, a flow for removing part of an outer cladding layer is set for the single-mode fibers at the output end, the tapering difficulty of the late tapering process can be reduced, the stretched length of cores of the optical fibers at the output end is reduced, and taper is small, so that fiber core size and numerical aperture change are small, butt joint with the optical fiber at the input end is facilitated, and the coupling efficiency is increased.