This　paper　proposes　a　diffuseness　estimation-based　single-source　time-frequency　point　(SSTP)　detection　method　for　multisource　direction　of　arrival　(DOA)　estimation.　According　to　the　composition,　time-frequency　(TF)　points　are　divided　into　three　types:　SSTP,　multisource　TF,　and　interference　TF.　SSTPs　and　multisource　TF　points　are　defined　as　weak　interference　time-frequency　points　(WITPs).　An　SSTP　is　a　TF　point　consisting　only　of　the　direct　component　of　one　sound　source,　which　is　beneficial　for　DOA　estimation.　Therefore,　multisource　DOA　estimation　is　transformed　into　single-source　DOA　estimation　by　SSTP　detection.　Diffuseness　estimation　is　introduced　for　a　sound　field　microphone　array.　WITPs　are　detected　by　a　diffuseness　estimation-based　detection　method.　Phase　similarity　determination　is　adopted　to　identify　SSTPs　from　detected　WITPs.　Multiple　sound　source　localization　is　completed　by　searching　peaks　in　the　normalized　histogram　of　DOA　estimates　corresponding　to　the　detected　SSTPs.　Experiments　demonstrate　that　the　proposed　method　achieves　the　precise　detection　of　SSTPs,　and　evaluations　show　that　it　has　superior　accuracy　of　multiple　sound　source　counting　and　localization　in　reverberant　and　noisy　environments.