If your husband doesn’t clear immigration to collect bags and stays in the international transit area, he can transit without a visa.
The requirements for this are:
- Arriving in Australia by aircraft
- Have a confirmed onward ticket within 8 hours
- Have valid documents for that country
- must not need to clear immigration or leave the airport transit lounge for any reason before boarding your onwards flight
These requirements are listed on the Australian home affairs website.
Note: If you do leave the transit area to collect bags you will need to get a transit visa, unless you are visa free to Australia anyway (depending on your nationality and citizenship)