We compute the Dirac spectral density of QCD in a wide range of eigenvalues by using the stochastic approach. The spectral density at relatively high eigenvalues can be used to extract the mass anomalous dimension. We use 2+1-flavor lattice ensembles generated with Mobius domain-wall fermion at three lattice spacings (a=0.083, 0.055, 0.044 fm) to estimate the continuum limit. The discretization effect can be minimized by a generalization of the valence domain-wall fermion. We compare the results with the perturbation theory available to O(alpha_s^4).