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The vertical Rayleigh-Sommerfeld (VRS) diffraction theory is used for analyzing and calculating the focused field distributions of high-numerical-aperture (NA) multi-step hybrid Fresnel zone plates (M-SHFZP). Under the illumination of linearly-polarized light, results are shown as follows: 1) Due to the transmission coefficient of the film changing with the depth of steps, the focused intensity of M-SHFZP is smaller than that of multi-step pure-phase Fresnel zone plates (M-SPFZP). However, the focal spot size of M-SHFZP is almost the same as that of M-SPFZP; 2) As the step number increases, the focused intensity increases, but the spot size is invariant; 3) The diffraction field presents a multispot distribution for low-NA M-SHFZP, but the intensity of high-order foci is effectively suppressed for high-NA M-SHFZP. The more the step number and the higher the NA, the stronger the ability of M-SHFZP to suppress higher-order foci. The results obtained by the VRS agree with the results obtained from the finite-different time-domain (FDTD) simulation basically.