To investigate the impact of group behavior on pedestrian evacuation under zero-visibility conditions, this paper combines controlled experiments with modeling and simulation for an in-depth analysis. Initially, by organizing experiments on pedestrian evacuation under zero-visibility conditions, the research identifies typical evacuation behaviors such as group behavior, auditory guidance behavior, and wall-following behavior. The pedestrians rely on auditory information to guide their companions during the process of forming groups. Pedestrian group behavior can be divided into three modes, and the walking speeds of grouped pedestrians vary depending on their spatial positions. By comparing and analyzing the walking speed and evacuation time of pedestrians under different grouping modes, it is found that group behavior under zero-visibility conditions reduces evacuation efficiency, while walking along the walls can improve evacuation efficiency. Subsequently, considering the movement characteristics of pedestrians in different group behavior modes, the influence mechanisms of auditory guidance and wall-following behavior on the evacuation process, a pedestrian evacuation model based on cellular automata under zero-visibility conditions is developed. Finally, the proposed model is validated using experimental results, and simulations are conducted to analyze the impact of group behavior on the evacuation process under zero-visibility conditions. By comparing and analyzing pedestrian movement trajectories and evacuation times in both the simulation and experimental processes, it is verified that the model can effectively reproduce the group evacuation process of pedestrians under zero-visibility conditions. When auditory guidance errors are considered, pedestrians exhibit wandering behavior in their movement trajectories. During the evacuation process, the greater the distance pedestrians can perceive each other for grouping, the higher the probability of group formation. As a result, groups are formed earlier, which decreases evacuation efficiency. This indicates that under zero-visibility conditions, group behavior negatively impacts the evacuation process. This research provides a scientific basis for the formulation of pedestrian evacuation strategies and plans in similar scenarios.