protected string urlParemeter=string.Empty;

    protected void Page_Load(object sender, EventArgs e)
    {
        if (Request.QueryString.HasKeys())
        {
             urlParemeter = Request.QueryString.ToString();
        }

        DataBind();
    }

------解决方案--------------------
<a href='dd.aspx?id=2&<%#Request.QueryString["ss"] %>'>链接1 </a> <a href='dd.aspx?id=3&<%=Request.QueryString["ss"]%>'>链接2 </a> <a href='dd.aspx?id=4&<%=urlParemeter %>'>链接3 </a>