Adjustable constant-volume sampling measuring cylinder

The utility model discloses an adjustable constant-volume sampling measuring cylinder which comprises a measuring cylinder body, a groove is formed in the outer wall of the measuring cylinder body, a water outlet is formed in the groove, first sealing strips are arranged at the upper end and the lower end of the water outlet respectively, and two openings are formed in each first sealing strip. Sliding grooves are formed in the outer wall, located on the two sides of the groove, of the measuring cylinder, and an adjusting assembly is arranged between the two sliding grooves; the measuring cylinder is simple in structure and novel in design, the position of the overflow opening is adjusted up and down according to the requirement of taking amount, so that the overflow opening corresponds to the needed scale line, a solution is poured into the measuring cylinder, a worker does not need to look at the scale line all the time, and when the solution reaches the designated scale line, the solution poured into the m