The invention provides a short-time proximate value weather forecasting system with the ultrahigh resolution ratio (cloud-resolving scale). The short-time proximate value weather forecasting system comprises a preprocessing subsystem, an assimilating subsystem, a forecasting subsystem and a postprocessing subsystem. The preprocessing subsystem is used for obtaining a background field, a boundary field and a radar retrieved wind field of a target area with the to-be-forecasted weather and generating a cloud analysis field according to the background field and the boundary field. The assimilating subsystem is used for conducting variation assimilation processing on the radar retrieved wind field and the cloud analysis field which are obtained by the preprocessing subsystem to obtain an initial field, and the initial field is subjected to cloud analysis processing to obtain a three-dimensional lattice position field. The forecasting subsystem is used for conducting data processing according to the three-dimensional lattice position field to obtain forecasting data. The postprocessing subsystem is used for generating comprehensive forecasting information according to the forecasting data. According to the short-time proximate value weather forecasting system provide by the invention, the fine forecasting level of a small-scale convection system in the to-be-detected area can be effectively increased.