Just now was trying to boot into Windows, by plugged in the HDMI cable, which supports for video only. But then, I rebooted into Linux without plugged out the HDMI cable. Then, it caused no sound in Linux.
Try 1: I killed the pulseaudio, then delete the ~/.config/pulse, and rebooted Linux. Failed.
Try 2: Run alsamixer, turned on everything, and do Try 1 again. Failed.
Then I guessed it was caused by the HDMI cable, which the Windows may assume there is audio, then caused my computer somehow ouptut the audio through the HDMI, even I rebooted into Linux.
Try 3: Plugged out the HDMI, booted into Windows. I checked the audio in Windows. It plays well. Then rebooted into Linux without plugged in HDMI. Yeah! It works. Passed.
Then I found that, though the sound works fine, my headphones doesn’t work. Tried out many methods as I asked in forum.
At the end, it is solved by shutdown, and boot again.