For developing high-order scheme with low dissipation and low dispersion to accurately simulate the flow field with complex structures such as shock wave, a method of stencil reorganization was proposed based on the fifth-order finite difference WENO-Z scheme. A four-point central stencil recombined by three-point stencils is introduced in the calculation of WENO nonlinear weight in order to optimize the weight allocation of each template in the original format, and two improved WENO-Z schemes were proposed. The dispersion and dissipation properties of the schemes were compared and analyzed via the approximate dispersion relation analysis, which shows that the dissipation of the two improved schemes decreases at different extent. The numerical experiments show that the improved schemes have better shock capture property and higher resolution for small-scale flow structures.