Influences of time delay on photoelectron spectra and state populations of nonadiabatic coupled NaI molecules in intense femtosecond pump-probe laser field are investigated by using three-state model and time-dependent wave packet method. Results show that the wave packet moves periodically on the potential energy surface with roundtrip time of 1000 fs. When time delay is 200 fs, the wave packet reaches the crossing region for the first time and splits into two parts. The wave packet returns to the crossing region and splits again at 800 fs. The periodical motion of the wave packet results in the periodical variation of photoelectron spectra peak position. The splitting situation of wave packet in the cross region affects the distribution of state populations. The wave packet motion control and selective distribution of state populations can be achieved by adjusting pump-probe delay time. The results can provide some reference for realizing the optical control of molecules and quantum control process experimentally.