The effects of pump intensity, pump wavelength and pulse width on state populations of three-level ladder K2 molecule driven by intense femtosecond pump-probe pulses are investigated and firstly quantified by employing the time-dependent wave packet method. The pump intensity, pump wavelength and pulse width affect Rabi oscillation, which results in the periodical change of the populations of electronic states. The effect of quantization field parameters on population of the excited state shows that the change frequency varies with increasing of pump intensity and pulse width. Results provide an important reference for realizing the molecule optical control in experiment and further study of K2 molecule dynamic properties.