Estimating　the　direction　of　arrival　(DOA)　is　an　important　topic　in　the　array　signal　processing.　This　paper　addresses　the　issue　of　multisource　localization　in　a　closed　environment.　We　propose　a　single　source　zone　(SSZ)　detection　method　based　on　first-order　relative　harmonic　coefficient　(RHC),　and　designs　a　dynamic　SSZ　detection　rule.　Finally,　2-D　kernel　density　estimation　(KDE)　and　peak　search　are　used　to　achieve　multisource　DOA　estimation.　The　proposed　method　is　evaluated　by　simulation　experiment　and　compared　with　the　reference　methods,　and　the　effectiveness　of　the　proposed　method　is　verified.