Studying bosonic analogues of fermions in topological electron systems is one of the hottest areas. They are featured by linear band crossing points at finite energy in the momentum space, topologically protected by symmetries. Since the excitations near these points can be described by Dirac or Weyl equations, these points are dubbed as Dirac or Weyl points, respectively. Topological bosons have been realized in artificial systems, e.g., phononic and photonic crystals. In contrast, although there are many theoretical proposals, real materials supporting topological bosonic excitations are rare. Recently, our group has observed the Dirac magnons in a three-dimensional antiferromagnet Cu3TeO6. This success encourages us to search for more systems that host topological magnons. In this proposal, we want to study on the topological magnon exctations in a honeycomb ferromagnet CrBr3.