During tunnel construction, a lot of dust is produced at the heading face, posing a threat to the health of construction personnel. Dust removal and air curtain (AC) systems are typically used to reduce and isolate dust, respectively. A mechanical mechanism based on jet technology is designed to form an AC. The incompressible N-S equations and the realizable k-ε turbulence model are used to simulate the jet AC and the air flow in the tunnel space, the calculation methods and settings used are verified to be reliable. The effects of the air supply duct (ASD) and its relative position on the AC equipment, air outlet baffle (AOB), and jet air volume on the AC were studied. The AOB can increase the inclination angle of the AC and velocity of the outer edge of the AC, and reduce the air leakage in the tunnel. The jet air volume has limited influence on the AC, and the installation of the ASD can improve the convergence of the AC, particularly when the ASD is located on a different side. The data and conclusions obtained from the simulation analysis can provide reference for the design and manufacture of jet AC.