The Multipurpose Reflectometer (MR) uses a time-resolved method to record reflected neutrons on the detector to obtain the relationship between the neutron reflectivity (R) and the momentum transfer vector (Qz). The thickness dependence of the scattering length density in the film can be obtained by analyzing the neutron reflectivity curve. The film thickness and interface roughness can then be determined. When the polarized neutron is used, the distribution of magnetization along the direction of the film growth can be obtained, and the surface and interface magnetic properties can be characterized using in-situ conditions such as temperature, magnetic field, and electric field.