Hi Yu Yuxuan
The only items that can be added to 'Tool set' or 'Quick tools' are the ones that appear under the 'Tools' option: http://tv.adobe.com/watch/acrobat-xi-tips-tricks/how-to-create-and-share-custom-tool-sets/
As you use 'Read Out Loud' frequently, it would be helpful to use the shortcut assigned to it - 'Ctrl (win)/Cmd (Mac) + Shift + Y'. Though you may add the 'Reading Options' in the 'Tool set' (follow the above video).
Thank you for your reply
I see the movie but I cannot find 'Reading Options' in the tool set
You can't find it because it is not there. Quick tools will usually only allow you to pick up stuff that has a button somehwre in the user interface. Read aloud does not have such a button.
Instead, as recommended abiove, use the keyboard shortcuts that already are assigned to the Read aloud functions, like Ctrl-Y to start Read aloud and Ctrl-V to start reding the current page.
Thank you, And I think the read aloud button may be your consideration in your future work