But the params just can get by jquery.Because I have a dropdownlist and a link, when user click the Link, this will use createUrl to redirect user to spectificed controller, and pass params by get the dropdownlist value.
Your id here will be added to the url. So you will try to load an URL like (depending on the url management rules):
/lichchay/exportexcel/id/$("#cbo").val()
Based on what you said, I think you should write a javascript function that will be called when the link is clicked. This function will construct the URL. Personnally, I would write something like this:
// Create the link with an id
echo CHtml::link('Export','#', array('id'=>'exportLink'));
// Create the url with a 1234 value as a placeholder
// You may have routes defined with id:\d+, that's why you should use an integer
$url = Yii::app()->createUrl('lichchay/exportexcel', array('id'=>1234));
// Replace the 1234 with the real id to use
Yii::app()->getClientScript()->registerScript("exportLinkScript", "
$('#exportLink').click(function(){
var id = $('#cbo').val();
var url = '{$url}';
window.location.href = url.replace('1234', id);
});
");