代码演示 横向合并：

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>演示table标记2--单元格合并</title>
        <style type="text/css">
            td{
                text-align: center;
            }
        </style>
    </head>
    <body>
        <table border="1" cellspacing="0" width="50%" height="150">
            <caption>横向合并单元格</caption>
<!--colspan中必须指定要合并的列数目，是两列还是三列等等-->        
            <tr> <th colspan="2">姓名和年龄</th> <th>电话</th> </tr>
            <tr> <td>Jack</td> <td>24</td> <td>1351234567</td>  </tr>
            <tr> <td>Tom</td> <td>22</td> <td>1351234567</td>  </tr>
            <tr> <td>Rose</td> <td>22</td> <td>1351234567</td>  </tr>
            <tr> <td>张三</td> <td>25</td> <td>1351234567</td>  </tr>
        </table>
        <br/>

        <table border="1" cellspacing="0" width="50%" height="150">

运行结果：
【HTML】table表格拆分合并（colspan、rowspan）-编程知识网
代码演示 纵向合并：

<table border="1" cellspacing="0" width="50%" height="150">
            <caption>纵向合并单元格</caption>
            <tr><th>班级</t> <th>姓名</th><th>年龄</th> <th>电话</th> </tr>
            <tr><td rowspan="2">601班</td> <td>Jack</td> <td>24</td> <td>1351234567</td>  </tr>
            <tr> <td>Tom</td> <td>22</td> <td>1351234567</td>  </tr>
<!--rowspan中必须指定要合并的列数目，是两行还是三行等等-->    
            <tr><td  rowspan="3">602班</td> <td>Rose</td> <td>22</td> <td>1351234567</td>  </tr>
            <tr> <td>张三</td> <td>25</td> <td>1351234567</td>  </tr>
            <tr> <td>李四</td> <td>25</td> <td>1351234567</td>  </tr>
        </table>
    </body>
</html>

【HTML】table表格拆分合并（colspan、rowspan）-编程知识网
原文：https://blog.csdn.net/qq_35415600/article/details/70237433