why my export to excel not separated by cells but by semicolon?

It appears that your CDT is a length of 1, with all of the values for each data point included in row 1.  Appian displays arrays separated by semi-colon.  You will want to confirm your CDT is set to multiple and is populated correctly.

You'll need to provide us with a bit more information on the configurations of the individual inputs (namely, the "Cdt" input, and as Chris already mentioned, the current value in whatever CDT pv you're feeding into it), if you hope for much useful feedback here.

thanks friends~! i forgot to set it to be multiple ;)  By the way, do you know why it sometimes report error "invalid contentID?" when import excel into database?