An automatic tray loading system and a use method of the same are provided, which includes a stacked tray assembly, including at least one tray which is stacked up, where the at least one tray is provided with several locating slots; a tray lifting platform which includes a tray supporting table being connected with a elevating mechanism; a tray pick and place platform having a working region covers a tray input module, where the tray pick and place platform includes a manipulator which is connected with a multidimensional motion mechanism; and a delivery table including a tray placement plate, where each of the tray placement plate is provided with a groove which is configured to place the at least one layer of trays, and each of the tray placement plates is connected with a linear driving mechanism.