Under the condition of limited observation time, the advantages of bar graphs and doughnut graphs in mapping data to the overall ratio relationship are studied. The experiment designed bar graphs and doughnut graphs of three sizes (7.5%, 15%, 22% of the screen) and three mapping values (1, 1/2, 1/3), the percentage of data is used for judgment to obtain the average value of the judgment time and the average error rate of the two forms. The experiment uses the computerized experiment generation system E-prime to collect data, and uses SPSS for data statistics and analysis. When the mapping value is 1, 1/2, 1/3, the average value of the judgment time of the three sizes of the bar graph is lower than that of the donut chart; the average judgment error rate of the bar graph is 2.51%, which is lower than that of the donut chart The error rate is 4.03%; the smaller the mapping value of the two graphs, the slower the judgment speed. The speed and accuracy of the mapping judgment of the bar graph is more advantageous than that of the doughnut graph, and it is more suitable for use in time- and space-constrained scenarios, which helps to reduce the information overload caused by data accumulation in the data visualization design.