Yes, then you can ask your relatives or friends to mail the card back to you in HK, you need the PR card to get back to Canada.
It is better to use a more secure way to mail the card back (e.g. Fedex) instead of regular air mail
"The permanent resident card (PR card)
If you travel outside Canada, the permanent resident card is your proof that you are a permanent resident of Canada. If you leave Canada, you will need this card to re-enter the country on a commercial vehicle, like an airplane, boat, train or bus.
If your permanent resident card expires, it does not mean you have lost permanent resident status."