A spherical polyelectrolyte brush is studied by self-consistent field theory (SCFT)and the results are compared with predictions from scaling theory.It is shown that the SCFT results give the general trends as well as insight into the crossover regions between different regimes. The density profiles of the polyions and small ions indicate that the systems are locally electroneutral.The salted brush bears characteristics similar to those of a neutral brush.Counter-intuitively，the chains are not uniformly stretched in the osmotic regime.The free-end monomers shift to the outer region and an exclusion zone appears and grows with decreasing of salt concentration.