The invention relates to Mn<4+>-activated oxyfluoride red phosphor and a preparation method thereof. The general chemical formula of the red phosphor is A2[MO2F4]:Mn<4+>, wherein A can be Na, K, Rb or Cs, and M is Mo or W. According to the red phosphor, charge compensation can be carried out by introducing ions such as Li<+>, K<+>, Na<+>, Rb<+>, Cs<+>, Ca<2+>, Mg<2+>, Zn<2+>, Ba<2+> and Sr<2+>, so that the luminescence property is further improved. The red phosphor provided by the invention has a good compensation effect when being applied to a white light-emitting diode. The red phosphor can be efficiently excited by blue light, is emitted in a narrow-band linear shape, is high in color purity and quantum yield and simple in preparation technology, and needs less hydrogen fluoride (HF) when being prepared.