Hi @Qing ,
Could you describe more clearly about what do you want?
Which one do you want
1)connect Excel with PowerApps?
2)import Excel to PowerApps?
3)import Excel/csv to CDS?
1)If you want to connect Excel with PowerApps, you need to upload your excel to one drive firstly.
And then, in the View pane, choose dat source, choose one drive, choose the file that you want to connect with.
After you connect with this file successfully, you could use its data in PowerApps.
2)If you want to import Excel to PowerApps, you just need to choose "import from Excel" in data source.
Then, you could display data of excel in PowerApps.
Please note that, in this situation, this is static data(read-only), you could only display data, can not update data.
3)If you want to import Excel/csv to CDS, you could choose "get data" in cds.
In the selection pane, you could choose excel or csv.
After you import data to CDS successfully, you could connect with this data in PowerApps by choosing related entity of CDS.
Best regards,