Modularized multifunctional line source simulation system

A modular multifunctional line source simulation system disclosed by the present invention comprises: a lower gas distribution module comprising a module body, a tracer gas channel, a tracer gas outlet and a plurality of tracer gas inlets, the tracer gas channel is arranged in the module body in a zigzag manner, the tracer gas outlet is arranged in the middle position of the top of the module body, and the tracer gas inlets are arranged in the module body; the plurality of tracer gas inlets are symmetrically formed in the two sides of the module body; the line source module is hermetically connected above the lower gas distribution module, a line source and a lane simulation unit are arranged on the line source module, the bottom of the line source is communicated with the tracer gas outlet, and the top of the line source is communicated with the lane simulation unit; and the pollutant testing unit is arranged at the outlet of the line source module. The device can visually observe and test the diffusion dist