I have no identity in Australia and was arrested by immigration. Will my deposit be confiscated by immigration?

No, but if you live in a private black market and the Australian government buys a plane ticket to send you back, you owe the Australian government the accommodation fee (more than 200 Australian dollars per day) and the plane ticket fee (not a discount, but a full ticket, about more than 2,000 Australian dollars), and you won't get any Australian visas in the future.

You'd better buy your own plane ticket, get a bridge visa E and leave the country on time.

It's no big deal that the visa is overdue, as long as you don't apply for refugees, don't cheat the Australian government, and buy a plane ticket to return to China.