Objective To investigate the different effects of small incision lenticule extraction(SMILE) and sub-Bowman keratomileusis (SBK) on ocular surface tear system. Methods A prospective study. Total of 63 eyes of 63 cases were selected randomly in this study. There were 33 eyes who underwent SMILE and 30 eyes who underwent SBK. Corneal fluorescein(FL) staining, tear break-up time (BUT), Schirmer I test (SIT), central corneal sensitivity and ocular surface disease index (OSDI) score were estimated periodically before and 3 months after surgery. Results The FL scores in SMILE group were lower than those in SBK group at 1 week postoperatively (Z=2.455, P=0.014). The BUT of SMILE group were larger than those of SBK group at 1 (t=2.432, P=0.018) at 3 months postoperatively (t=2.150, P=0.036). The central corneal sensitivity was observed in SMILE group at any visit postoperatively were higher than that in SBK group (P 0.05). Conclusion The effect of SMILE surgery on ocular surface tear system is smaller than that of SBK. And the former recovers with less time. Key words: Small incision lenticule extraction; Sub-Bowman keratomileusis; Ocular surface; Tear