Variable-caliber additive manufacturing device and control method

The invention discloses a variable-caliber additive manufacturing device and a control method. The device comprises a feeding mechanism, a variable-caliber discharging mechanism and a four-axis movement mechanism, and the feeding mechanism is arranged on the four-axis movement mechanism; the variable-caliber discharging mechanism comprises an upper connecting disc, a lower connecting disc and a rotating disc, and the upper connecting disc, the lower connecting disc and the rotating disc are coaxially assembled so that the rotating disc can rotate around a center shaft between the upper connecting disc and the lower connecting disc. The upper connecting disc is connected to the feeding mechanism in a sleeving manner; the plane where the lower end of an output hole of the feeding mechanism is located coincides with the upper surface of the rotating disc, a center hole formed in the center of the rotating disc is coaxial with the center of the output hole, and the rotating disc rotates to change the angle betwee