The invention discloses a pneumatic control valve with a single valve core. The pneumatic control valve comprises a base, a pneumatic control valve body, a valve deck plate and the valve core. The pneumatic control valve body is provided with a containing cavity for the valve core to move vertically, the valve core is installed in the containing cavity, and springs axially installed are arranged between the pneumatic control valve body and the valve core; the base is connected to the bottom end of the pneumatic control valve body in a sealed mode, and the valve deck plate is connected to the top end of the pneumatic control valve body in a sealed mode; the base is provided with one or more work channels, and the valve deck plate is provided with a gas channel for receiving compressed gas; the valve core is driven to synchronously press the work channels in the base by gas pressure, so that the work channels are sealed and isolated, and the valve core is driven to be reset by the elastic stress of the springs, so that the work channels realize circulation. According to the pneumatic control valve, one or more work channels are blocked simultaneously through one valve core, the pneumatic control valve is especially suitable for the occasion when two work channels need to be blocked simultaneously and synchronously, and the problem that a differential pressure leak detector cannot control two work channels synchronously when controlling the two work channels simultaneously is solved.