This dissertation presents searches for lepton flavor violating decay of the standard model Higgs boson into a muon and a tau lepton or to an electron and a tau lepton. Data collected by the CMS detector in 2016-2018, in proton-proton collisions at the LHC, at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 137 fb^-1 was used to perform the search. The observed (expected) upper limits on the branching fraction of Higgs boson decaying into a muon and a tau lepton were set at 0.15 (0.15)% at 95% CL and the branching fraction of Higgs boson decaying into an electron and a tau lepton were set at 0.22 (0.16)% at 95% CL. These are the most stringent limits set on these processes to date.