A magnetic resonance imaging (MRI) system for infants and children and imaging method thereof are disclosed. The system includes: a base; a housing, with a bottom fixed to the base; a monitoring shield, pivotably connected to the top of the housing; a pair of open magnets, which are spaced apart from each other and fixed to the base by a magnet holder such that an imaging area is defined between them; an operating table, fixed in the imaging area; an incubator, movably connected to the operating table and configured to house an infant or child and to adjust the position of the infant or child in the imaging area. The monitoring shield has a closed configuration and an open configuration. In the closed configuration of the monitoring shield, the magnet holder, the open magnet, the operating table and the incubator are all situated within a space delimited by the base, the housing and the monitoring shield. With this optimized structure, the system allows a radiologist to more accurately and intuitively adjust