Create multiple file attachment field in Infopath form

Perform the following steps to create a multi-file attachment in InfoPath:

1. Add a Repeating Table with 1 column to your InfoPath form template.
2. Go to the Data Source task pane and double-click the field under the repeating node for the Repeating Table.
3. Change the Data type to Picture or File Attachment (base 64) and click OK.
4. Right-click the field in the Repeating Table on the InfoPath form template, and select Change To, and then File Attachment from the context menu that appears.

That is how you can attach multiple files in InfoPath.