Test tube rack with adjustable pore size

The utility model discloses a test tube rack with an adjustable pore size. The test tube rack comprises a base, test tube rack partition plates, test tube rack transverse plates, base stand columns, crossed round hole devices and test tubes, a test tube rack partition plate is arranged in the middle of the upper end of the base; test tube rack transverse plates are respectively arranged at the left and right ends of the upper side of the test tube rack partition plate; a test tube clamping opening is formed in the test tube rack transverse plate; test tubes are placed in the test tube clampingopenings; base stand columns are arranged on the base on two sides of the test tube rack partition plate; a crossed circular hole device is arranged on the test tube clamping opening; a crossed roundhole device is arranged at a test tube clamping opening for placing a test tube; a limiting ring at the upper end of an inner groove of the tightening outer sleeve is clamped and embedded into a slideway on the outer side of