Abstract: The present invention is to provide a vortex device for treating exhaust gas of an internal combustion engine, which comprises a first housing having a first end surface and a second end surface; a first inlet positioned on the first end surface and connected to an exhaust tube of the internal combustion engine; a first outlet positioned on the second end surface; a first baffle board fixedly connected to the housing, having a plurality of gas holes; a first vortex mechanism connected to the first baffle board; and a catalytic filter. The invention also provides a system for treating exhaust gas from the internal combustion engine. The system comprises the vortex device, the first treating device, and/or the second treating device and/or a fourth treating device as the internal combustion is a diesel engine.