Thanks to the guide and its participants, I successfully installed OS X 10.11.4 on my XPS 15 9550.
The guide is considerably perfect. Just follow the steps and you’ll get a well-done Hackintosh.
My Clover directory, DSDT & SSDT and Kexts are uploaded to Github, for reference only.
Update: Now I upgrade to 10.11.5, and everything is fine.