The invention discloses a reaction spraying preparation method of oxide eutectic ceramic amorphous powder, relates to a preparation method of oxide amorphous powder, and aims at solving the problems that a conventional amorphous ceramic preparation method is relatively low in ceramic conversion rate, high in cost and not applicable to industrial production and no preparation method for ultrahigh temperature eutectic ceramic amorphous powder is available in the field. The reaction spraying preparation method comprises the following steps: I, drying nitrate, thereby obtaining a nitrate reaction agent; II, drying metal powder, thereby obtaining a metal powder reaction agent; III, drying pressure control metal powder, thereby obtaining a pressure control agent; IV, drying oxide powder, thereby obtaining a diluent; and V, ball-milling and mixing the above raw materials, filling into a reaction spraying device, igniting the raw materials to initiate the reaction, keeping the temperature for certain time after obtaining melt, opening a nozzle for spraying, curing, drying, and subsequently grinding, thereby obtaining the oxide eutectic ceramic amorphous powder.