Energetic Neutral Atoms (ENA) are generated within the Earth's magnetosphere through charge exchange between magnetically trapped energetic ions and cool neutral gasses. An ENA imager can potentially record the arrival directions and energies of magnetospheric EN As, as well as provide (indirectly) global images of the spatial and energy distributions of their parent ion populations. Preliminary technical configuration and simulation of the Neutral Atom Imaging System for high energy neutral atoms (NAIS-H) designed for the Chinese Magnetospheric-Ionospheric-Thermospheric (MIT) mission are described. In inherited the design concept of NUADU and focus on the main scientific objective of MIT and t.lie orbit, a preliminary technical overview of this instrument is provided. The simulations under a dipolar magnetic field model show tliat the instrument has the capability to monitor global dynamic processes with high temporal and spatial resolution.