This work presents a cell-based smoothed finite-element method (CS-FEM) for simulating strongly coupled non-Newtonian fluid-structure interactions. The governing equations of a Carreau-Yasuda fluid and an elastic solid are discretized by the CS-FEM, which softens all gradient-related terms. The stress equilibrium along the interface is also derived from the CS-FEM notion. After discussing a two-level mesh-updating strategy, the strong coupling between the two physical media is realized via the block Gauss-Seidel iterative procedure. Numerical examples are presented to demonstrate the performance of the proposed method.