The invention discloses a workshop welding fume collecting device. The workshop welding fume collecting device comprises an air suction cover and an air guide cover. The tapered air guide cover communicates with the upper end of the air suction cover, an airtight cylindrical motor enclosure is fixed to the position, on the lower portion of the air guide cover, of the interior of the air suction cover through a fixing rod, a vertical motor is fixed to the interior of the motor enclosure, and a motor shaft of the motor penetrates through the motor enclosure; and a rubber seal ring is arranged atthe position where the motor shaft penetrates through the motor enclosure in a sleeving mode, the interior of an opening in the lower end of the air suction cover is covered with a filter supportingmesh, fan blades blowing upwards are fixed to the motor shaft, and a circular disc between the fan blades is supported on the filter supporting mesh. The fan blades are driven to rotate through the motor, so that airflow blowing upwards is formed, the airflow is matched with suction force of a pipeline, thus the air suction capability of the air suction cover is greatly improved, and the dust collection effect is better; and the motor is completely isolated from the outside world, the good dustproof effect is achieved, and prolonging of the service life of the motor is facilitated.