Neutron scattering has emerged as a pivotal experimental technique for resolving static magnetic structures and dynamic magnetic excitations in materials at the atomic scale, owing to the intrinsic magnetic moment of neutrons, their characteristic length and energy scales (angstrom wavelengths and meV energies), and strong penetrating power. In recent years, the exploration of unconventional magnetic structures in quantum materials has imposed increasingly stringent requirements on characterization techniques. This paper reviews the development and state-of-the-art applications of neutron scattering in magnetic materials research, with particular emphasis on its unique advantages and current challenges in resolving complex magnetic orders. Specifically, elastic neutron scattering techniques (e.g., neutron diffraction, total scattering, diffuse scattering, small-angle neutron scattering, and neutron reflectometry) allow the precise determination of non-collinear, non-coplanar, helical, conical, and skyrmion-lattice magnetic structures. Inelastic neutron scattering directly measures the magnetic excitation spectrum, i.e., the dynamic structure factor S(Q, ω), thereby enabling the extraction of exchange parameters, magnetic anisotropy, and spin gaps. These methods have enabled important advances in altermagnets (e.g., the observation of magnon chirality splitting in MnTe), quantum magnets (e.g., the Bose-Einstein condensation of bound magnons in Na₂BaNi(PO₄)₂), single-molecule magnets, and unconventional superconductors (e.g., magnetic resonance modes in iron-based and nickelate superconductors). However, several key challenges remain, including weak magnetic signals arising from limited neutron flux and small sample volumes, the trade-off between resolution and intensity, strong neutron absorption by elements such as Gd and Sm, high incoherent background from hydrogen-containing compounds, the diffculty of characterizing thin-film magnetic structures, and the complexity of in situ experiments under extreme conditions such as low temperature, high pressure, and high magnetic field. Moreover, the data reduction and inverse modeling required for systems with multi-q magnetic orders, coexisting short-range and long-range correlations, and multi-domain effects demand advanced algorithms and high-performance computing. Looking ahead, the integration of neutron scattering with complementary techniques, such as synchrotron X-ray scattering, muon spin relaxation, nuclear magnetic resonance, and Lorentz transmission electron microscopy, will enable multi-scale and multimodal cross-validation. The emergence of altermagnets and other newly proposed magnetic concepts offers fresh opportunities for polarized neutron studies. Artificial intelligence and machine learning are expected to accelerate the determination of magnetic structures from scattering data. Meanwhile, next-generation neutron facilities, such as the China Spallation Neutron Source Phase II (CSNS-II), the European Spallation Source (ESS), and the Spallation Neutron Source Second Target Station (SNS STS), will significantly enhance neutron flux and instrumental resolution. In particular, CSNS-II will increase the beam power from 185 kW to 500 kW, enabling the routine characterization of weak magnetic signals, small samples, and rapid dynamic processes. Overall, neutron scattering, empowered by instrumental innovations, multimodal collaborations, and data-driven methodologies, is expected to play an even more central role in uncovering exotic magnetic phenomena and advancing condensed matter physics.