The invention discloses a synthesizing method of an Sr2MgSi2O7:Eu2+, Dy3+ nanowire with a long afterglow lighting function. The synthesizing method comprises the steps of dissolving Mg(NO3)2, Sr(NO3)2, Eu(NO3)3 and Dy(NO3)3 into a mixed solvent of water and ethanol to prepare nitrate mixed solution with the total concentration of metal ions being 0.02-0.05mol/L, then adding Na2SiO3 solid into nitrate mixed solution to obtain white turbid liquid, adjusting the pH value to be 2-3, then adding macromolecule template agent, moving into a hydrothermal kettle and sealing, reacting for 2-4h at 150 DEGC-180 DEG C, pouring out reaction solution, naturally cooling the reaction solution to room temperature, and filtering the reaction solution to obtain a white precipitate, conducting vacuum drying on the white precipitate for 10-20h at 80 DEG C-110 DEG C, and putting the white precipitate into a muffle furnace, and forging under reducing atmosphere to obtain the MgSr2SiO4:Eu2+, Dy3+ nanowire with long afterglow lighting function, which is 30-60nm in diameter and 4mum in length. The synthesizing method has the characteristics of simple process, low energy consumption, uniform product size, no agglomeration, excellent lighting performance and the like, and provides a new approach for the research of nano long afterglow materials.