  Two-dimensional semi-Dirac models describe a family of novel materials that
have anisotropic dispersion with relativistic-type spectrum along one of the
spatial directions and non-relativistic along another. In the present paper we
perform a detailed analysis of Landau levels collapse for such models in
perpendicular magnetic field and in-plane electric field by using
semi-classical approach and tight-binding simulations. The anisotropic nature
of semi-Dirac dispersion manifests itself in the possibility of Landau level
collapse for only one of the electric field directions. In addition, the
topological transition with merging Dirac cones has its own distinct features
in Landau level collapse.
