A drinking straw device includes a molded elastic sheet having a curved base portion, a first bent portion, and a second bent portion. The first and second bent portions are disposed at two opposite sides of the curved base portion to permit an inward surface of the first bent portion to overlap an outward surface of the second bent portion. The first and second bent portions are respectively imparted with an inward biasing force and an outward biasing force so as to bring the inward surface of the first bent portion and the outward surface of the second bent portion into frictional and abutting engagement with each other to thereby allow the molded elastic sheet to constitute a straw tube extending along a tube axis.