The three-body decays B 0 s → ψ(2S, 3S)π + π − are studied based on the perturbative QCD approach. With the help of the nonperturbative two-pion distribution amplitudes, the analysis is simplified into the quasi-two-body processes. Besides the traditional factorizable and nonfactorizable diagrams at the leading order, the next-to-leading order vertex corrections are also included to cancel the scale dependence. The f 0 (980), f 0 (1500) resonance contributions as well as the nonresonant contributions are taken into account using the presently known ππ time-like scalar form factor for the ss component. It is found that the predicted B 0 s → ψ(2S)π + π − decay spectra in the pion pair invariant mass shows a similar behavior as the experiment. The calculated S-wave contributions to the branching ratio of B 0 s → ψ(2S)π + π − is 6.0 × 10 −5 , which is in agreement with the LHCb data B(B 0 s → ψ(2S)π + π − ) = (7.2 ± 1.2) × 10 −5 within errors. The estimate of B(B 0 s → ψ(3S)π + π − ) can reach the order of 10 −5 , pending the corresponding measurements.