/***    使用书签进行图片替换的核心代码    ***/
            Document doc = new Document();
            Paragraph paragraph = doc.createParagraph();
            DocPicture picture = paragraph.appendPicture(imagePath);//imagePath图片路径
    		picture.setWidth(width);
    		picture.setHeight(height);
    		picture.setVerticalAlignment(ShapeVerticalAlignment.Center);
    		picture.setHorizontalAlignment(ShapeHorizontalAlignment.Center);
            // 设置图片段落居中
    	    paragraph.getFormat().setHorizontalAlignment(HorizontalAlignment.Center);
            // 定位书签位置并将书签处的文本替换成图片
    	    BookmarksNavigator bookmarkNavigator = new BookmarksNavigator(doc);
    	    bookmarkNavigator.moveToBookmark(bookmark);//bookmark是Word中书签的名称
            Paragraph oldParagraph = bookmarkNavigator.getCurrentBookmark().getBookmarkEnd().getOwnerParagraph();
            DocumentObjectCollection childObjects = oldParagraph.getOwner().getChildObjects();
            int indexOf = childObjects.indexOf(oldParagraph);
            childObjects.remove(oldParagraph);
            childObjects.insert(indexOf, paragraph);

Spire.Doc用来操作Word非常方便，提供的API文档也很全，不足的是文档中关于示例代码很少，平时开发Word报告时，查找起来比较麻烦。