The present study is mainly motivated to develop an unsteady computational code that simulates a transient behaviour of the spray injected into a moderately high-pressure environment. The moderately high-pressure regime is introduced to minimize some of the complexities that arise from considering the high pressure. In order to represent the spray development, the DDM (discrete droplet model), which is often identified as the PSIC (particle-source-in-cell) model, is employed among the SF (separate flow) models. Here, the Eulerian-Lagrangian formulation is used to analyse the two-phase interactions. For an accurate prediction of droplet evaporation rate in a high-pressure environment, a proper high-pressure evaporation model is applied using thermodynamic and phase equilibrium conditions. Also, the effects of high pressure as well as high temperature are considered in the calculation of liquid and gas properties. Throughout the numerical simulation, a transient thermo-fluid mechanical behaviour of spray in a high-pressure environment is traced and visualized while its physical meaning is discussed in comparison with the case for normal pressure. Regarding the evaporation of spray, the effect of interactions between droplets is examined in comparison with the case for single droplet.