Based on Landau-de Gennes theory, the stability of split-core configuration confined in nematic liquid crystal droplets with submicron scale under homeotropic anchoring boundary condition is investigated. Results show that there are radial and ring structures under the strong anchoring boundary condition and single constant approximation. According to the difference of the radius, the two structures will become stable respectively, i.e., the ring structure is stable when the radius is larger, and the radial structure is stable when the radius is smaller. Under the condition of elastic anisotropy, a stable ring structure and a metastable split-core structure will appear. Furthermore, the results show that if the effect of k24 on the internal structure of the droplet is considered, when the boundary anchoring condition is changed from strong anchoring to weak anchoring (take anchoring strength w=10-4J/m2 as an example) and under the single constant approximation, it is found that there would be three structures, i.e., radial structure, ring structure and uniform state structure, and the radial structure is stable state, in addition, the stability among structures is not affected by the effect of k24; under the condition of elastic anisotropy, the radial structure is transformed into the split-core structure. And it is still metastable when the effect of k24 is not considered; if the effect of k24 is considered, the split-core structure can be stable when the size and elastic anisotropy are within a certain range. In our simulation, it is found that the effect of k24 can make the split-core structure become stable for the first time.