The invention discloses a method for preparing ball teeth by co-sintering ceramics/ metal. The method comprises the following steps: A, uniformly mixing zirconium oxide powder being 25-50nm in particle size and paraffin based on the mass ratio of (98-99): 1; B, uniformly mixing 4140 high-strength alloy steel powder being 80-120 microns in particle size and paraffin based on the mass ratio of (98-99): 1; C, inserting a thin sheet in a die; filling two sides of the thin sheet with the zirconium oxide powder and the 4140 high-strength alloy steel powder; drawing out the thin sheet; and pressing along the thin sheet inserting direction to obtain a green body, wherein the density of the ceramics end is 45-50%, and the density of the metal end is 70-75%; and D, sintering the green body in a vacuum degree of (1-2)*10-2Pa; increasing the temperature at the rate of 2-3 DEG C per minute; maintaining temperature for 2-3h under the temperature of 1300-1350 DEG C; and then cooling together with a furnace until room temperature is reached. With the adoption of the method, the co-sintering performance of the zirconium oxide ceramics and the 4140 high-strength alloy steel powder can be improved; and meanwhile, the sintering temperature range is reasonably selected and effectively controlled, so that the combining intensity of a metal and ceramics boundary can be improved.