Owing to its special magnetic structures, magnetic cloud (MC) is the main driver of disaster space weather. This paper deals with the research of MC on three aspects including boundary layer, azimuthal flux and large-scale structure. The boundary layer exists in the boundary of MC due to magnetic reconnection taking place there. Such reconnection could peel off the magnetic field of MC as it propagates, causing the reduction and imbalance in the azimuthal flux of its magnetic flux rope structure. Multiple flux ropes are often detected within MC. The coalescence of these flux ropes could change the large-scale structure of MC. In addition to exchange reconnection, magnetic reconnection taking place near the boundary of MC could also open the closed or half-closed magnetic field lines of MC. Although great progress has been made, many questions about the evolution of MC are still open. If MC could evolve into an interplanetary small magnetic flux rope due to the ``peeling off'' effect? Could the interaction of these sub-flux ropes within MC lead to collapse of the magnetic flux rope structure of MC? To answer these questions, further studies based on theory, observation and numerical simulation are needed.