This paper aims to analyze the allocation of cognitive resources to icon depth in different types of interfaces. Through an eye movement tracking experiment, the behavioral response data indexes were obtained when searching for three kinds of depth icons in a single depth icon sets and a mixed depth icon sets, and the participants' subjective satisfaction evaluations of each depth were collected on this basis. It was found that there are significant differences in search quality between different depth icons. The depth of the search target was negatively correlated with the efficiency of visual search in a single depth icon sets. In the mixed depth icon sets, the search efficiency of medium depth target icon was the highest; There was no significant difference in terms of the effect of different depth icons on cognitive load; In addition, the participants' subjective evaluation results of the three types of icons showed that the medium depth icons have higher subjective satisfaction. Stimulants of graphic depth affect people's choice of search strategy. Grasping the characteristics of individual icon design elements is as important as, paying attention to the influence of different interface environments. Using icons of medium depth can increase the recognizability and differentiation of icons, improve the quality of visual search, and provide a better user experience in mixed depth icon sets.