The invention discloses a teaching experiment device for coal rock permeability. The teaching experiment device comprises a jet device, a guide bracket and an experiment table, wherein the jet device comprises a barrel, a compression head, a telescopic inner barrel, a piston, a compression spring and a pull rod, the telescopic inner barrel is arranged at the front part of the inside of the barrel, the front end of the telescopic inner barrel is connected with the front end of the inside of the barrel, the rear end of the telescopic inner barrel is connected with the front end face of the piston, the rear end of the piston is connected with the pull rod and the compression spring, and the rear end of the compression spring is connected with a spring seat at the rear end of the barrel; the compression head is arranged in the center of the front end of the barrel, the diameter of the compression head is smaller than that of the barrel, the interior of the compression head is hollow, the rear end of the compression head communicates with the barrel, and a small hole is formed in the front end of the compression head; the guide bracket is mounted above the experiment table, and the guide bracket is composed of four inclined frames and one sliding sleeve. The teaching experiment device for coal rock permeability is simple in structure and low in cost, the area of jet transmission can be intuitively observed through the naked eyes, the transmission area reflects the magnitude of the coal rock permeability, the visualization degree is high, and the teaching experiment device is suitable for teaching experiments and demonstration.