Micro constant-speed dropping funnel

The utility model relates to the technical field of chemical engineering experimental instruments, in particular to a trace constant-speed dropping funnel which comprises a dropping funnel body and a first constant-pressure tube, a piston is arranged in the middle of the dropping funnel body, the dropping funnel body is divided into a dropping funnel upper portion and a dropping funnel lower portion by the piston, and the first constant-pressure tube is arranged in the first constant-pressure tube. The first constant-pressure pipe is communicated with the upper part of the dropping funnel and the lower part of the dropping funnel, a grinding connector is arranged at the lower part of the dropping funnel, a dropping nozzle is arranged in the grinding connector and is communicated with the upper part of the dropping funnel, a liquid bin is arranged between the upper part of the dropping funnel and the piston, and the piston is arranged in the liquid bin. One side of the liquid bin communicates with the first co