The utility model discloses a data acquisition device for measuring stem flow. The device comprises a drainage tube and a water accumulating barrel, wherein an annular disk of a water collecting tube at the front end of the drainage tube is wound around a stem, and the other end of the annular disk is connected to the water accumulating barrel. The water collecting tube of the drainage tube is a semi-open hose, and an opening makes close contact with the stem. The stem flow is totally collected through a stem winding type structure, and thus the acquisition accuracy is guaranteed. The data acquisition device is further provided with a filtration blocking screen, and therefore foreign matter is prevented from blocking an acquisition tube. The data acquisition device is simple in structure, convenient to use and flexible to move, and various electronic detection devices can be carried in the water accumulating barrel.