In optical diffraction tomography with specimen rotation,the set of captured frequencies exhibits a missing space called missing apple core,an algorithm,in which Fourier mapping algorithm was combined with iterative constraint algorithm,was proposed to acquire the missing frequencies and reconstruct a high-resolution refractive index map.First,based on the theory of digital holographic microtomography with sample rotation,the experiment system was set up and the digital holograms were acquired at regularly-spaced angular positions within 360° viewing angle.Then,the complex field images were calculated from the holograms.Last,the high-resolution three-dimensional refractive index map was reconstructed by the proposed algorithm.The experimental results demonstrate that the algorithm is feasible and effective for acquiring the missing apple core frequencies and achieving the high-resolution three-dimensional refractive index distribution.