直接上代码：

library(openxlsx)
#创建演示的三个dataframe
df1 = data.frame(Mark=c(21, 102, 13, 88),
                 ID=c('AA', 'BB', 'BB', 'CC'))
df2 = data.frame(Mark=c(100, 120, 121, 154),
                 Grade=c(7, 8,7.5, 10))
df3 = data.frame(Mark=c(11, 42, 55, 64),
                 points=c(17, 14, 22, 24))
#为表格命名
names <- list('Sheet1' = df1, 'Sheet2' = df2, 'Sheet3' = df3)
#输出表格
write.xlsx(names, file = 'data.xlsx')