Multi-exciton　generation　by　multi-photon　absorption　under　low-energy　photons　can　be　thought　a　reasonable　method　to　reduce　the　risk　of　optical　damage,　especially　in　photoelectric　quantum　dot　(QD)　devices.　The　lifetime　of　the　multi-exciton　state　plays　a　key　role　in　the　utilization　of　photon-induced　carriers,　which　depends　on　the　dynamics　of　the　exciton　generation　process　in　materials.　In　this　paper,　the　exciton　generation　dynamics　of　the　photon　absorption　under　low-frequency　light　in　CdSe　QDs　are　successfully　detected　and　studied　by　the　temporal　resolution　transient　absorption　(TA)　spectroscopy　method.　Since　the　cooling　time　of　hot　excitons　extends　while　the　rate　of　auger　recombination　is　accelerated　when　incident　energy　is　increased,　the　filling　time　of　defect　states　is　irregular,　and　exciton　generation　experiences　a　transition　from　single-photon　absorption　to　multi-photon　absorption.　This　result　shows　how　to　change　the　excitation.　Optical　parameters　can　prolong　the　lifetime　of　excitons,　thus　fully　extracting　excitons　and　improving　the　photoelectric　conversion　efficiency　of　QD　optoelectronic　devices,　which　provides　theoretical　and　experimental　support　for　the　development　of　QD　optoelectronic　devices.