The invention discloses an automatic coating device for a high-performance soldering flux. The automatic coating device comprises a coating flow platform, a dynamic conveying mechanism and a verticaldisplacement coating mechanism, wherein the vertical displacement coating mechanism comprises a seal box and a position control box; a mobile positioning mechanism is arranged in the position controlbox; a soldering aid coating head is fixedly mounted on the mobile positioning mechanism and comprises a soldering flux storage pipe and a discharge port, the discharge port comprises a bullet mountedin the soldering flux storage pipe and a thin discharge hole formed in the bullet, a spherical cutting hole groove is formed in the bottom of the bullet; a rotary coating ball is arranged in the spherical cutting hole groove; a material flowing port is formed in the upper end of the spherical cutting hole groove, an I-shaped flow control part is arranged in the material flowing port, a push-up force application cambered surface is arranged at the lower end of the I-shaped flow control part, and a round closing plate is arranged at the upper end of the I-shaped flow control part. According tothe scheme, the coating port can be closed automatically, so that resource waste caused by overflowing of the soldering flux is avoided, and soldering-aid performance of the soldering flux is prevented from being affected due to exposure in air.