The utility model relates to a gas separation unit technical field provides a molecular sieve adsorption tower for oxygenerator, include a tower section of thick bamboo, locate molecular sieve and thefirst board that flow equalizes in the tower section of thick bamboo, the molecular sieve is located the first board top of flow equalizing, first flow equalize the board with forming first space between the diapire of a tower section of thick bamboo and the lateral wall, and being equipped with evenly distributed's first gas pocket on the first board that flow equalizes, the porosity is 30% to 80%, the diameter of first gas pocket is 20 microns to 1 millimeter. The utility model discloses a set up the first board that flow equalizes for the air can flow to the molecular sieve more uniformly,has improved the availability factor of molecular sieve.