Hello haibin88 and welcome to Seven Forums.
Couple of things you can try. Sometimes a piece of dirt or food particle gets stuck under a key and causes weird things to type out. A can of compressed air may dislodge the detritus.
Malware can cause problems. Run a full scan with your installed anti-virus suite and then run a secnd on-demand scan with the free Malwarebytes
Double check your keyboard settings in control panel > keyboard > hardware tab. See if the device is working properly.
Also in control panel > region and language > keyboards and languages > change keyboards > advanced key settings > make sure your keyboard is set for the correct region/language and you don't have hotkeys set up.
USB devices attached to the computer could be interfering. Unplug them.
Plug in a different USB keyboard to see if problem continues. If it does you may have a hardware issue with the laptop.