在雅思写作中，描述双饼图时，你可以遵循以下结构：

引言 ：简要介绍饼图的主题和目的。

总体描述：

概述两个饼图所展示的数据，并指出它们之间的主要差异。

详细分析：

分别对两个饼图中的各个部分进行具体分析，比较不同类别之间的比例大小。

结论：

总结主要观点，并可能对未来趋势进行展望或提出建议。

具体步骤如下：

引言

开始时，清晰地介绍图表的主题和目的。例如：“The charts illustrate the proportion of...”。

总体描述

提供两个饼图所展示数据的总体概述，并指出它们之间的主要差异。例如：“The first pie chart shows the distribution of... while the second pie chart highlights...”。

详细分析

分别对两个饼图中的各个部分进行具体分析，比较不同类别之间的比例大小。例如：“In the first pie chart, the largest segment is... accounting for...%. In contrast, the second pie chart reveals that...”。

结论

总结主要观点，并可能对未来趋势进行展望或提出建议。例如：“From these charts, it is evident that... Looking ahead, we can expect...”。

示例

假设你要描述两个饼图，一个是某公司的销售额分布，另一个是不同产品线的销售额占比。

引言：

The charts illustrate the sales distribution of a company over two years, comparing the proportion of sales across different product lines.

总体描述：

The first pie chart shows the sales distribution in 2022, while the second pie chart displays the sales distribution in 2023. The primary difference between the two charts is the shift in the market share of the top three products.

详细分析：

In 2022, the largest segment in the first pie chart is Product A, accounting for 35% of total sales, followed by Product B with 25% and Product C with 20%. In 2023, Product A still leads with 30%, but Product C has gained significant ground, now at 25%, while Product B has dropped to 20%.

结论：

From these charts, it is evident that there has been a notable shift in the company's sales landscape over the past year. Product C has emerged as a strong contender, potentially indicating a successful marketing strategy or changing consumer preferences. Looking ahead, the company should focus on maintaining its momentum in Product C while also addressing the decline in Product B's market share.

通过以上步骤和示例，你可以有效地描述双饼图，使文章结构清晰、逻辑性强，并突出主要观点。