You may need a visa for Brunei if you have a Chinese passport
Visa options for Brunei
Visa on arrival is required for trips longer than 14 days for Tourism
Travellers need a visa to visit Brunei for Tourism and Business for more than 14 days. Travellers do not need a visa if staying for 14 days or less. Travellers can get a visa on arrival in Cambodia at the port of entry, such as an international airport or border crossing.
This is not offered by sherpa°.
Apply on the government site.