Can I take a backpack and a suitcase with me on China Oriental International Flight?

First, make sure your luggage compartment is the boarding box. Some boxes are too big to carry. If the backpack is not too big, there is no problem at all, but if it is a big backpack, it depends on luck.

The general requirement of carry-on luggage is 10 kg. It's okay to exceed one or two kilograms, but if it's too much, it should be checked.

Weight is a factor. What is more important is the size of your luggage. You can take it up if it can fit in the overhead luggage compartment. It's much more convenient if your luggage has wheels. You can't see if it's heavy when you pull it in. If it is portable, try to put it in a lighter box. They don't usually check.

I hope it helps you.