There is usually a Tax Treaty between countries that specifies how taxation is handled. Details can vary between your home country and other countries for the same circumstance.
For example, in Canada it used to be that, for pilots specifically, if tax was paid in one jurisdiction none was owed in the other. That has since changed and tax is paid in Canada less the credit for tax paid in Korea.
It is different with China.
It is best to have a tax expert confirm the details for you I would say.