We have analyzed the experimental data obtained by NA50 Collaboration in Pb-Pb collisions at 158A GeV/c. By assuming the QGP phase transition in central Pb-Pb collisions and its 100% suppression to J/ψ, we correct the differential cross section of J/ψ production in high-energy heavy-ion collisions based on the theory of J/ψ absorption by nucleons and comovers. The theoretical result fits the experimental data well.