The invention relates to the technical field of product marking equipment, in particular to an automatic number sprayer and an automatic number spraying method employing the automatic number sprayer. The automatic number sprayer comprises a manipulator, a number spraying assembly, a feeding device and a control cabinet, wherein the manipulator is arranged on a base which can move horizontally; the control cabinet is in communication connection with the manipulator, the base, the number spraying assembly and the feeding device; the manipulator is a six-degree-of-freedom manipulator; the number spraying assembly is arranged at the free end of the manipulator; the feeding device is connected with a nozzle device and feeds raw materials to the number spraying assembly; the control cabinet controls the movement of both the base and the manipulator and controls the number spraying assembly to make the raw materials into metal drops and then spray the metal drops to a billet to be subjected to number spraying. The automatic number spraying method utilizes the automatic number sprayer. According to the automatic number sprayer and the automatic number spraying method, the automatic operations of finishing positioning and changing the number spraying position by the manipulator are conducted, so that the problems of inaccurate positioning and large occupied space in the prior art are solved.