1, the principal can usually be recovered after the insurance expires, because the premium of this kind of insurance is usually high, and the actual guarantee is only to pay the cost through the interest of this premium, so the principal may be recovered at the expiration of the contract or when the principal and interest are added.
2. Consumer insurance often can't get back the principal after it expires, because the premium of this kind of insurance is very low and the leverage is very high. A few hundred yuan can buy tens of thousands of yuan of protection, and you can get high compensation if something goes wrong during the insurance period. If there is no accident, the premium will not be refunded.
Whether the deposit can be refunded depends on the specific types of insurance and insurance contracts, and is judged by the insurance company.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.