The invention discloses a multi-purpose weir flow device suitable for teaching experiment. The multi-purpose weir flow device comprises a water storage tank, an on-weir water supply head part, an opentrench water channel, a shutter tail door and a multi-purpose weir mechanism, wherein the multi-purpose weir mechanism comprises a rectangular thin-wall weir, a practical weir face and a wide-top weir face; the rectangular thin-wall weir is a vertical face; the practical weir face comprises a practical weir face vertical face and a practical weir face curved face; the wide-top weir face comprisesa wide-top weir face top face, a wide-top weir face left plumb face, a wide-top weir face right plumb face and a wide-top weir face inwards curved face; the practical weir face is connected with therectangular thin-wall weir through the practical weir face vertical face, and the wide-top weir face is connected with the practical weir face vertical face of the practical weir face through the wide-top weir face right plumb face. Compared with the prior art, the multi-purpose weir flow device has the advantages that by utilizing the change of the weir body structure, the diversified weir formsare realized, multiple purposes are realized through one tank, the weir flow is diversified, the effect is obvious, the seepage and leakage preventing effects are good, the weir body is stable, the cost is relatively low, the structure is concise, and the popularization space is large.