China Life Fu Lushou has bought it for a full year. Can I turn myself in? Can the principal be refunded in full?

You have paid 10 years. Why do you want to return it? In fact, you can return it at any time, just to see if it is cost-effective. I don't know if the product at that time had a loan function. Now many products have loan function. If you need money badly, you'd better not pay it back. If you have to pay it back, the annual cash value of 10 will be higher than the initial return ratio.

Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.