How to import data that we create in exel must link in our form, it's for the students just compare their data correct or incorrect...

Yes, the data can be imported into form Submissions from Excel or CSV file. However, the Excel/CSV file should have special format depending on your form fields. Please check the guide below for more information:

http://www.jotform.com/help/308-Import-App-Easily-import-your-Excel-or-CSV-data-into-JotForm

If you have any question or issues, please do not hesitate contacting us. We will be glad to assist you.

I have problem when I try to understanding on your explanatioan above to implay  on the form, for helping in easy would you mind if give me toturial about that....

What my colleague said is that, you can import your Excel data in your form but, the data format in your Excel sheet need to match the one in the form.

A tutorial on that can be found from this link:  Import-your-Excel-or-CSV-data-into-JotForm.