Hi Sun Rui,
You can add the .sptxt file to Skyline directly as a spectral library by doing the following:

• Settings > Peptide Settings - Library tab
• Click the Edit List button
• Click the Add button
• Give the library a name
• Click the Browse button - and choose your .sptxt file
• Click OK to add the library
• Click OK to close Edit List
• Make sure your new library is checked
• Click OK to close the Peptide Settings form

Once you have added the library, how you use it will depend on your intended experiment. If you will choose a limited, targeted subset of the peptides in your library for a method like SRM/MRM or PRM, then the best place to start would be doing the Targeted Method Editing tutorial:

https://skyline.ms/wiki/home/software/Skyline/page.view?name=tutorial_method_edit

Which has been translated to Chinese:

https://skyline.ms/wiki/home/software/Skyline/page.view?name=tutorial_method_edit_zh

If you will be analyzing DDA data, then you should also look at the MS1 Full-Scan Filtering tutorial:

https://skyline.ms/wiki/home/software/Skyline/page.view?name=tutorial_ms1_filtering

Again translated to Chinese:

https://skyline.ms/wiki/home/software/Skyline/page.view?name=tutorial_ms1_filtering_zh

If you will be analyzing DIA data, then I would recommend the ETH tutorial on DIA analysis with Skyline:

http://dia-swath-course.ethz.ch/downloads.html

Which we recently translated to Chinese for the Shanghai course:

https://skyline.ms/project/home/software/Skyline/events/2018 Shanghai Course/participants/begin.view

You can find it in the "ETH" subfolder on this page.

Hope this helps. Thanks for making the effort to begin using Skyline in your research.

--Brendan