NOVELTY - A lithium ion polymer electrolyte film is high amorphous phase polymer substrate generated from free radical copolymerization of large monomer of polyethylene oxide (PEO), small monomer of alkenes and azodiisobutyronitrile; the substrate is formed into the lithium ion polymer electrolyte film by removing solvent in inert gas atmosphere with flow casting method after compounding with lithium tetrafluoroborate (LiBF4) and lithium (Li)- beta -aluminum oxide (Al2O3) nano-powder in inert gas atmosphere into lithium ion polymer electrolyte.    USE - The lithium ion polymer electrolyte film is useful for preparing lithium ion polymer battery.    ADVANTAGE - The lithium ion polymer electrolyte film has excellent mechanical property, steady chemical property and high electrical conductivity. The prepared lithium ion polymer battery is made with ferric phosphate lithium as anodic material and electrolyte film as membrane barrier. This battery can have good electrochemical property, large capacity and long re-charging service time, safe and reliable charging and discharging processes. Manufacturing process is simple and convenient, which can obtain high rate of finished products and cost low. Furthermore, the prepared anodic and cathodic sheets are even in texture, and performances of the products are homogeneous; and it is convenient for combining into battery pack to work.    DETAILED DESCRIPTION - A lithium ion polymer electrolyte film is high amorphous phase polymer substrate generated from free radical copolymerization of large monomer of PEO with 200-1000 of average molecular weight, small monomer of alkenes and azodiisobutyronitrile according to 1:1-100:0.01-0.11 of mol ratio at 70-90 degrees C; the substrate is formed into the lithium ion polymer electrolyte film by removing solvent at 40-60 degrees C in inert gas atmosphere with flow casting method after compounding with LiBF4 and Li- beta -Al2O3 nano-powder in inert gas atmosphere into lithium ion polymer electrolyte; this electrolyte film has 0-20wt.% of LiBF4 and 5-30wt.% of Li- beta -Al2O3 nano-powder; and electrical conductivity of this electrolyte film at room temperature is 3.5-6.2\10-3 S/cm. INDEPENDENT CLAIMS are:    (1) a preparation method of a lithium ion polymer electrolyte film; and    (2) a manufacturing method of lithium ion polymer battery containing the lithium ion polymer electrolyte film comprises (1) preparation of anodic sheet: (a) mixing ferric phosphate lithium, acetylene black, polyvinylidene fluoride with N,N-2-methyl pyrrolidone according to 100:1.0-5.0:2.8-15.0:80-150 of weight ratio for stirring for at least 1 hour, to make its viscosity coefficient reach 2000-20000 bp.s; (b) spreading the slurry obtained in the previous process on aluminum foil uniformly, where density of coating is 50-200 g/m2; and rolling it to 1.5-3.0 g/cm3 of volume concentration after drying at 80-150 degrees C; and (c) cutting out it according to size, and welding tag to it as well as carrying out insulating treatment; (2) preparation of cathodic sheet: (a) mixing graphite, saturated polyester, sodium carboxymethyl cellulose and styrene-butadiene with water according to 100:0.5-3:0.5-2:2-6:100-150 of weight ratio for stirring for at least 1 hour, to make its viscosity coefficient reach 2000-20000 bp.s; (b) spreading it on copper foil uniformly, where density of coating is 25-150 g/m2; and rolling it to 1.0-1.8 g/cm3 of volume concentration after drying at 80-150 degrees C; and (c) cutting out it according to size, and welding tag to it as well as carrying out insulating treatment; and (3) assembling of battery: stacking the anodic and cathodic sheets dead against to each other and separating using polymer electrolyte film; setting into a metal casing or composite aluminum plastic film after heat pressing, and sealing and activating it.