In the engineering field, operators need to face complex information interfaces with unevenly distributed stimuli and perform related interactive tasks. Visual attention allocation of operators has been proved to be closely related to task performance. However, the potential connection between visual attention allocation by multi-priority stimuli based on different information allocation strategies and task performance in complex interfaces requires further investigation. In this study, task performance and visual behavior of operators under different load conditions are studied on the basis of the experiment of the multi-priority attention allocation strategy. The experimental results indicate that the differential allocation strategy and information priority division improve the task performance, and the visual behavior differs significantly under different allocation strategies and priorities and is affected by mental loads. This conclusion can provide a reference for the design and optimization of human-computer interfaces and thus improve the task performance of operators.