The invention provides a quantum dot single photon source and a preparation method thereof, and a preparation method of a device of the quantum dot single photon source. The quantum dot single photonsource comprises a substrate, a buffer layer, and / or a DBR reflection layer, an absorption layer, an active layer, a cover layer, and a quantum dot array, wherein the buffer layer is arranged on the substrate, the DBR reflection layer is arranged on the buffer layer, the absorption layer is arranged on the DBR reflection layer, the active layer is arranged on the absorption layer, the cover layeris arranged on the active layer, the quantum dot array is obtained by etching the cover layer and the active layer, and the quantum dot array is located on the absorption layer. The fluorescence emissivity of the quantum dot single-photon source device is improved, and the yield of the manufactured quantum dot single-photon source device is improved.