A method of producing graphite and metallic catalyst composite for diamond synthesis, with the characteristics including the following steps: a. The clean high-pure graphite particle will at first be placed in a heating chamber for preheating the graphite particle with the protection of vacuum or nitrogen and argon gas. The pre-heating temperature of said heating chamber is set to be higher than the boiling point (t f) of a metal carbonyl compound to be selected from a group of compounds consisting of Fe 5, Co 2 8, Ni 4 and Mn 2 10 for plating. The upper limit of temperature is set depending on the thickness of plating layer with the temperature being set to be higher when the thickness of the plating layer of the product increases, wherein the specific temperature is determined by calculating the quantity of energy which is used to decompose said metal carbonyl compound and the pre-heating temperature is adjusted between t f and t f +800°C; b. The heated graphite particles then shall be fed into a plating room with a vibrator or agitator and then an inlet switch of the steam of carbonyl metal complex as the coating will be opened to feed the steam of metal carbonyl from a vaporizing room into the plating room; after that, the vibrator or agitator will be operated and the metal carbonyl decomposes on the graphite surface forming metal layer to the graphite surface evenly by means of the heat of the heated graphite; c. The coated graphite particles then will be fed into the cooling and passivating room for cooling and passivating of the discharging materials or enter the next round circle of heating and coating until it reaches up to the needed coating thickness; finally, the composite materials will be cooled, passivated and packaged. a. The clean high-pure graphite particle will at first be placed in a heating chamber for preheating the graphite particle with the protection of vacuum or nitrogen and argon gas. The pre-heating temperature of said heating chamber is set to be higher than the boiling point (t f) of a metal carbonyl compound to be selected from a group of compounds consisting of Fe 5, Co 2 8, Ni 4 and Mn 2 10 for plating. The upper limit of temperature is set depending on the thickness of plating layer with the temperature being set to be higher when the thickness of the plating layer of the product increases, wherein the specific temperature is determined by calculating the quantity of energy which is used to decompose said metal carbonyl compound and the pre-heating temperature is adjusted between t f and t f +800°C; b. The heated graphite particles then shall be fed into a plating room with a vibrator or agitator and then an inlet switch of the steam of carbonyl metal complex as the coating will be opened to feed the steam of metal carbonyl from a vaporizing room into the plating room; after that, the vibrator or agitator will be operated and the metal carbonyl decomposes on the graphite surface forming metal layer to the graphite surface evenly by means of the heat of the heated graphite; c. The coated graphite particles then will be fed into the cooling and passivating room for cooling and passivating of the discharging materials or enter the next round circle of heating and coating until it reaches up to the needed coating thickness; finally, the composite materials will be cooled, passivated and packaged.