In order to improve the working environment inside the mine, to reduce the mine accident rates, this paper established a pipeline fluid models based on tunnel modeling theory. And on this basis, using CAD rendered 2D models of pipeline mechanical ventilation fluid field, using COMSOL Multiphysics simulated the model and solved the numerical value. In addition, this paper made in the implementation of the metal mine site piping mechanical ventilation system. The experimental results show that the content of harmful gases, dust particle inside the mine ventilation have been reduced very large. Except the reference point 5 the rest four points oxygen content have certain of ascension. This system improves the working environment inside the mine. Besides the outlet maximum speed of 11.6m/s, with digital simulation results obtained close to the pipe diameter is 1.06m, which is consistent with the actual situation.