The sputum sucker includes an outer tube and an inner axially slidably disposed in the outer tube. A normally-closed valve and a sleeve are disposed at a front end and a rear end of the outer tube, respectively. A bracket is fixed at a rear end of the inner tube. A connecting handle is articulatorily connected between the sleeve and the bracket. A torsion spring is disposed between the bracket and the connecting handle for normally exerting a force on the bracket to push the outer tube forwards. The normally-closed valve will seal up the inner tube when the connecting handle is not forced. The normally-closed valve will be broken open by the inner tube when the connecting handle is operated to pull the outer tube rearwards, and the normally-closed valve clings to the suction head to clean up while the normally-closed valve is being broken open and moved rearwards.