In this work, we investigate a direct variational formulation for imaging reconstruction of near-field holotomography, in which Fresnel diffraction and tomographic projection are treated jointly within a single nonlinear forward operator. We derive the mathematical properties of the forward operator, establish Fr\`{e}chet differentiability and convergence guarantees under nonlinear Landweber iteration, and develop a TV-regularized and phase-guided Bregman scheme for stable numerical reconstruction. Numerical and experimental studies confirm that the proposed framework achieves accurate and stable three dimensional reconstructions of both the phase and absorption components.