The advancements in understanding the dynamic behaviors of nematodes in fluid environments were reviewed, with foci on their individual locomotion and mechanical responses in various environments, collective aggregation behaviors, theoretical modeling, numerical simulations, and external control strategies. The Caenorhabditis elegans, owing to its advantages such as ease of observation, high culturing survival rates, and short life cycles, has become a widely used model organism in fluid dynamics research. It serves as a valuable platform for uncovering the physical principles of life motions under non-equilibrium conditions and for advancing the development of bioinspired micro/nano systems. Current research faces major challenges, including deciphering the multi-scale coupling mechanisms among neural, muscular, and fluidic systems, in situ capturing of the microscopic emergence processes of collective behaviors, establishing a unified multi-scale computational framework, and achieving synergistic and precise control via multi-physical fields. To date, studies have mechanistically elucidated the adaptive principles of individual locomotion and the emergence mechanisms of collective behaviors, developed cross-scale theoretical models and high-fidelity numerical simulation methods, and innovated external control strategies utilizing multi-physical fields. Future research will focus on advancing high-resolution multimodal measurement technologies, validating multi-scale integrated models, innovating multi-physics field control strategies, developing AI-driven methodologies, and improving open-source scientific ecosystems. These efforts aim to deepen the understanding of fundamental principles of biological motions and provide theoretical supports for breakthroughs in advanced biomimetic systems and biomedical technologies.