@heiheshang: Since you can SSH into the device, let's get you set up.
1. Partition and Format your SD card's remaining, unused space (which will become mmcblk0p2)
2. Enter blkid | grep mmcblk and you should see mmcblk0p2 listed; the UUID number here is required below where it says [YourUUID]
3. Edit /mnt/mmcblk0p1/cmdline.txt and add this to the end of the existing string of text:
tce=UUID="[YourUUID]" opt=UUID="[YourUUID]" home=UUID="[YourUUID]"
Once finished, reboot and then log back into the device.
Run the program tce-ab and Search (one at a time) for each of the following extensions and Install them:
wifi
wireless_tools
wireless (and select wireless-#.#.#-piCore-v#.tcz)
wpa_supplicant
...and I think RasPi3's had a special firmware package, so search for
rpi3b
...it will begin with firmware-rpi3b-something if it still exists.
You should now be able to test for wifi connectivity. If everything done above is successful, your extensions should be available automatically after you reboot again. IF SO, return here to the forum - there have to be plenty of RasPi posts on how to set up and PERSIST your wpa settings for every time you reboot.