The invention discloses a ventilation port device for a building equipment room. The ventilation port device comprises a diffuser body, wherein a circular air inlet, an arc transition section, wedge-shaped air outlets and sealing partition plates are arranged on the diffuser body; the wedge-shaped air outlets and the sealing partition plates are arranged on the diffuser body at intervals; the wedge-shaped air outlets are arranged along the arc surface of the diffuser body at intervals; the adjacent wedge-shaped air outlets are separated by the sealing partition plates; and air flows in via thecircular air inlet and then flows out via the wedge-shaped air outlets arranged at intervals through the arc transition section connected with the circular air inlet. According to the ventilation port device, the effects of the air supply uniformity and the air supply accessibility in the equipment room are better, and the ventilation effect is good; and the problems of complicated air pipe arrangement, large initial engineering investment, large energy consumption, high engineering cost and short air outlet jet range in an existing building equipment room are solved, and the air supply of anair conditioner is uniformly distributed in the whole equipment room.