在Android EasyExcel中處理復雜表頭可以通過自定義表頭樣式來實現。以下是一個示例代碼來處理復雜表頭：

// 創建Excel表格
ExcelWriter excelWriter = new ExcelWriter("path/to/excel/file.xlsx");

// 創建表頭樣式
WriteCellStyle headCellStyle = new WriteCellStyle();
headCellStyle.setFillForegroundColor(IndexedColors.GREY_25_PERCENT.getIndex());
headCellStyle.setFillPatternType(FillPatternType.SOLID_FOREGROUND);
WriteFont headFont = new WriteFont();
headFont.setFontHeightInPoints((short) 12);
headCellStyle.setWriteFont(headFont);

// 創建Sheet對象
WriteSheet writeSheet = EasyExcel.writerSheet("Sheet1")
    .registerWriteHandler(new CellWriteHandler() {
        @Override
        public void beforeCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, CellData cellData, Cell cell, Head head, Integer integer, Integer integer1, Boolean aBoolean) {

            // 自定義表頭樣式
            if (head.getHeadNameList().contains("header1")) {
                cell.setCellStyle(headCellStyle);
            }

        }

        @Override
        public void afterCellCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, CellData cellData, Cell cell, Head head, Integer integer, Boolean aBoolean) {

        }

        @Override
        public void afterCellDataCreate(WriteSheetHolder writeSheetHolder, WriteTableHolder writeTableHolder, List<CellData> list, Cell cell, Head head, Integer integer, Boolean aBoolean) {

        }
    })
    .build();

// 寫入數據
List<List<String>> head = new ArrayList<>();
head.add(Arrays.asList("header1", "header2", "header3"));
List<List<String>> data = new ArrayList<>();
data.add(Arrays.asList("data1", "data2", "data3"));
excelWriter.write(head, data, writeSheet);

// 關閉ExcelWriter
excelWriter.finish();

在上面的代碼中，我們創建了一個自定義的表頭樣式headCellStyle，并將其應用到指定的表頭列上。通過實現CellWriteHandler接口，可以在寫入Excel表格時進行定制化處理，以處理復雜的表頭結構。