Based on a hierarchical basis a posteriori error estimator,
an adaptive weak Galerkin finite element method (WGFEM) is proposed
for the Stokes problem in two and three dimensions.
In this paper, we propose two novel diagonalization techniques for velocity and pressure, respectively.
Using diagonalization techniques,
we need only to solve two diagonal linear algebraic systems
corresponding to the degree of freedom to get the error
estimator. The upper bound and lower bound of the
error estimator are also shown to address the reliability of the
adaptive method. Numerical simulations are provided to demonstrate
the effectiveness and robustness of our algorithm.