Whether you are required to pay tax on income from outside China depends on whether you are considered to be resident or non-resident. Non-residents have to pay tax on income earned in China, but not on their
global income.
Residence is defined as having lived in China for
six consecutive years or more, and having spent an average of 183 days (i.e., more than half the year) in China during that year. It doesn’t matter whether these 183 days are continuous or interrupted, it’s the total number of days during the year that counts.
If you are deemed to be resident, you’re liable for tax on all your income anywhere in the world for any tax year where you’ve spent 183 days or more of that year in China, wherever that income was earned.
It’s also important to understand the difference between “resident” and “domiciled”.
Your domicile is your long-term home, usually (but not always) your country of nationality. If you have been granted permanent residence in China, you are likely to be considered domiciled in China.
Anyone domiciled in China is liable to taxation on all their income from anywhere in the world. This applies even if you are also required to pay tax in the territory where the money was earned.