The invention discloses a labyrinth sealing structure with concave sealing teeth. The core of the labyrinth sealing structure is that the sealing teeth are designed by means of a concave arc and the concave arc is determined according to the section height of a throat part, the perpendicular transition distance between the concave arc and tooth tips and the width of the tooth tips. By means of a flowing channel composed of the concave sealing teeth and a sealing rotor of the labyrinth sealing structure, the frequency relevance of sealing effective damping can be enhanced, the cross-over frequency of effective damping items is reduced, and therefore the frequency range of sealing safe and stable running is enlarged, and the aim of enhancing the stability of the sealing rotor is realized. Inaddition, the design of the concave sealing teeth is not related to the sealing gap changes, and therefore the tight sealing performance can still be ensured by controlling a sealing gap. It is shownthrough numerical value research that the cross-over frequency of the sealing effective damping items can be reduced by 6.4% or above by means of the labyrinth sealing structure with the concave sealing teeth after reasonable parameter design.