eth0      Link encap:Ethernet  HWaddr 00:23:24:a0:a1:5e  
          inet addr:172.20.1.143  Bcast:172.20.1.255  Mask:255.255.255.0
          inet6 addr: fe80::223:24ff:fea0:a15e/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:185999 errors:0 dropped:1 overruns:0 frame:0
          TX packets:158606 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:169522156 (169.5 MB)  TX bytes:19356563 (19.3 MB)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:47624 errors:0 dropped:0 overruns:0 frame:0
          TX packets:47624 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1
          RX bytes:4350067 (4.3 MB)  TX bytes:4350067 (4.3 MB)

wlan0     Link encap:Ethernet  HWaddr 48:8a:d2:3b:a4:55  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

the usb wifi adapt is rtl8188eu-master(driver)

insmod 8188eu.ko failure

(wlan0 ERROR while getting interface flags: No such device)

just need recompile the driver and insmod again.......

sudo ifconfig eth0 down

sudo ifconfig wlan0 up

everythings go fine.