It mainly deals with the properties for the principal curvatures of the hypersurface and gets two sufficient conditions under which S has a second gap.Also estimates for the gap s length are obtained.

• 通过对此超曲面主曲率的研究，给出了S的可能值存在第二空隙的两个充分条件，并分别估计了在这些条件下的空隙长度。