NOVELTY - Forming selenide nanofiber by double-crucible method, static electricity spinning of selenide, and combining spinning selenide and knitting technology involves: forming spinning solution by adding hexahydrate zinc nitrate and polyvinylpyrrolidone (PVP) to N,N-dimethyl formamide; forming zinc oxide nanofiber by spinning liquid in static spinning device and curing to obtain PVP/hexahydrate zinc nitrate nanofiber, which is heated in furnace; and forming zinc selenide nanofiber by using selenium powder, carbon rod and double-crucible method, placing crucible in furnace and cooling.    USE - For preparing selenide nanofiber by double-crucible method (claimed), which is useful for preparing laser display, flat panel display, in biomedicines, solar battery panel, storage and transmission device, scintillator, chemical sensor and biosensor, detector, and in catalytic fields such as processing information on light emitting diode.    ADVANTAGE - The method for forming selenide nanofiber by double-crucible method results in selenide nanofiber having diameter of 70-140 nm, length of more than 100 mu m, and good crystal structure. The method for preparing selenide nanofiber is simple, is applicable for large scale production, and has broad application prospects.    DETAILED DESCRIPTION - Method for preparing selenide nanofiber by double-crucible method, static electricity spinning of selenide, combining electrostatic spinning of selenide with knitting technology, and using polyvinylpyrrolidone (PVP) as macromolecule template agent, N,N-dimethyl formamide (DMF) as solvent, and selenium powder as selenylation reagent, to prepare ZnSe nanofiber product, involves: preparing spinning solution by weighing an amount of hexahydrate zinc nitrate (Zn(NO3)2.6H2O) and PVP, adding into DMF solvent at room temperature under magnetic stirring for 4 hours, and standing for 2 hours to form spinning solution, where the spinning solution contains (mass%) zinc (8), PVP (14), and DMF (78); preparing ZnO nanofiber in liquid pipe by spinning of spinning liquid into spinning device providing static spinning, having nozzle diameter of 1 mm, and spray head and horizontal plane at 30 degrees , by applying direct current voltage of 18 kV, curing to 20 cm, at room temperature to 18-25 degrees C, and relative humidity of 50-60% to obtain PVP/Zn(NO3)2 composite nanofiber, which is than put in program control temperature furnace for heat treatment, in which temperature is increased to 700 degrees C at rate of 1 degrees C/minute, kept for 4 hours, and then temperature is decreased to 200 degrees C at rate of 1/minute, and naturally cooled to room temperature to obtain ZnO nanometer fiber; and preparing ZnSe nanofiber by using selenium powder as selenylation reagent, and using double-crucible method, where selenium is placed into small crucible, is covered on carbon rod, so that ZnO nanofiber is in carbon rod, placing small crucible in large crucible, adding superfluous between crucibles and selenium powder, placing crucible cover, and placing external crucible in tubular furnace, introducing argon gas for 30 minutes at room temperature, keeping air in discharged tube, increasing temperature at speed of 5 degrees C/minute to 700 degrees C, which is maintained for 3 hours, then cooling at speed of 5 degrees C/minute to 200 degrees C, and naturally cooling to room temperature to obtain ZnSe nanofiber having diameter of 70-140 nm and length of more than 100 mu m.