Abstract: An automatic activator coating device for wire and arc additive manufacture includes a base, a mechanical arm is arranged on the upper side of the base, a clamping mechanism is arranged at the lower end of the mechanical arm, a container bottle is clamped on the clamping mechanism, one end of the container bottle is communicated with a sprayer, one end of the sprayer is communicated with an atomizing nozzle, the container bottle is communicated with the gas bottle, and a gas pressure regulating valve is arranged on the gas bottle; and a piston partition is arranged in the sprayer, the container bottle is communicated with an activator converging cavity in one end of the sprayer, a piston rod and a resetting mechanism are arranged in a mounting cavity in the other end of the sprayer, an open hole is formed in the inner surface of the sprayer