The invention discloses a preparation method for a high-temperature high-pressure photoelectric sensing material SrB4O7:Sm<2+>. The method comprises the following steps of: weighing H3BO3 according to a molar ratio of H3BO3 to SrCO3 which is equal to 4:1; adding the Sm2O3 in an amount according to required doping amount; stirring to dissolve H3BO3 in a water bath of 40 DEG C; adding HNO3 after H3BO3 is fully dissolved, wherein the amount of the added HNO3 is equal to the volume of the existing H3BO3; then adding weighed SrCO3, Sm2O3 and a proper amount of citric acid; placing mixture in a water bath of 90 DEG C to heat until the mixture becomes gel; placing the gel in a controllable electric furnace to remove moisture through evaporation and continuously heating until the gel spontaneously burns; taking the burned sample to grind; and placing in a high-temperature furnace of 880 DEG C to calcine for 3 hours to obtain pink fluorescent powder SrB4O7:Sm<2+>. The fluorescence intensity of the SrB4O7:Sm<2+> prepared by the sol-gel method is stronger than that synthesized by a high-temperature solid-phase method, the peak is sharper, and the SrB4O7:Sm<2+> is more suitable to be used as the high-temperature high-pressure photoelectric sensing material.