PL/SQL Tool import Chinese garbled

Plsql import Chinese, will appear garbled, how to solve?

Open PL/SQL, help---support information under character sets under Nls_lang, whether there is configuration information, if not, go to the environment variable configuration to add the corresponding configuration

Character Sets
Character Size:4 Byte (s)
charsetid:873
ncharsetid:2000
Unicode Support:true
nls_lang:simplified Chinese_china. ZHS16GBK
Nls_characterset:al32utf8
Nls_nchar_characterset:al16utf16

(Win7, other systems similar) My Computer--Properties--Advanced system configuration--environment variables--Add system variable Nls_lang, attribute value: Chinese_china. Zhs16gbk

After confirming, restart the plsql, and then insert the database into the Chinese data operation again;

PL/SQL Tool import Chinese garbled