The solid-state nonlinear optical(NLO)materials play critical roles in the extension of laser frequencies tunnable through unltravoilet to infrared spectroscopic regions.In the past decades,the development of NLO materials has made great progress,but it is still a challenge to develop novel solid-state materials with significant NLO properties particularly applied in mid-to-far infrared region.We present the recent advances in the computational studies on the second-order NLO properties of solid-state materials within the first principle DFT framework.The studies revealed some potential NLO materials:(1)the strain-induced improvements of second-order NLO response of strontium tetraborate crystal opening a new way to exploring NLO crystals;(2)simulations of LO and NLO properties of mercury iodate crystal predicting its applications in IR region;(3)evolutions of the structure-NLO property relationship of the multifunctional NLO material NaAsSe2 crystal.The computational study using quantum chemical approximations such as DFT methods now becomes an important tool to accelerate the discovery of advanced NLO solid-state materials.Our presented results showed the efforts along this way.