I just wondering that is it possible to load local data files(like .xlsx or .csv files that on my google drive) into Colaboratory?
Yes, all of these scenarios are supported.
For recipes to access local and Drive files, check out the I/O example notebook.
For access to xls files, you'll want to upload the file to Google Sheets. Then, you can use the gspread recipes in the same I/O example notebook.
A recently added way to upload local files is to use the 'Files' tab in the right hand side drawer.
From there, you can upload a local file using the 'upload' button.
(You can also download files by right clicking on them in the file tree.)