[Sodium battery: GEM has been authorized for "Metal ion doping, sodium ion battery cathode material coated with sodium titanium aluminum phosphate and its preparation method and application"]. Steps: Mix the sodium battery precursor, sodium source, aluminum source, titanium source, phosphorus source and alcohol to produce the metal ion doped sodium titanium aluminum phosphate coated sodium battery cathode material; The metal doping elements in the metal doping source solution include at least one of ruthenium, iridium, platinum and calcium.