I want to immigrate to Canada and Australia, but I signed a post contract (that is, a labor dispatch contract) with the company in the past two years. Does it matter?

You can leave your job after the expiration of the contract without restriction; You are only responsible for the contract you signed. If the contract has not expired, the contract you signed has a breach clause, whether it is a labor contract or a post contract, you should be held accountable;

If you go through the immigration formalities during the labor dispatch contract, the sending unit will suffer from the loss of interests and your immigration opportunities will be challenged. The company can intervene in your immigration procedures through lawyers.

If the above two points are all right, your immigration will not be affected. Use your "dispatch contract" and relevant visas to prove your work experience.

Wish you success!