Intelligent ventilation in underground engineering is a necessary guarantee for personnel health and safety risk control, characterized by complex system branches, diverse ventilation scenarios, and dynamic changes in ventilation load. To clarify the development mechanism of ventilation fluid in complex tunnel groups, optimize the design of ventilation fluid path parameters, and improve the feedback control and regulation capabilities, this paper constructs an intelligent ventilation experimental system for complex underground projects: Firstly, a method for calculating ventilation system parameters and indicators by coupling real-time monitoring, field simulation, and network solution is proposed; secondly, an intelligent ventilation control system based on closed-loop control theory is established, which has the functions of comprehensive perception of environmental and ventilation parameters, field network solution analysis of tunnel group ventilation parameters, real-time control of variable frequency fans and air regulation facilities, and continuous optimization driven by knowledge; thirdly, taking the Xulong project underground tunnel group as the prototype, a tunnel group model structure is established using an abnormal scale design, and hardware facilities such as sensors, variable frequency fans, air valves, and control cabinets are configured. Combined with the construction ventilation scenario as needed, the intelligent ventilation experimental platform is applied in practice, including the analysis of airflow structure and pollutant transport characteristics in large-span factory space, the coupling and optimization of natural and mechanical ventilation in the overall structure of the tunnel group, and the feedback control and management of the ventilation system’s energy-saving operation according to different construction intensities. The research results of this paper provide effective support for the intelligent control and management of ventilation in underground tunnel groups throughout the entire cycle, including system design, equipment selection, on-site regulation, and management evaluation, and can serve as a reference for similar projects.