Can I do a visa run from Thailand to Malaysia and return within 24 hours on a Non-B visa?

I think you are confusing exiting/re-entering by a LAND border (from the south) which some borders are now making people stay in Malaysia for 24 hours with flying in and out which you can do as fast as you can switch planes and fly back into the country.

so you have a year-long, multi-entry Non-B visa where you bounce out and back every 90 days?

> need to go visa run very soon but someone told me need to go out more than 24hours from Thailand.

To my knowledge, that's a law that's occurring on the Malaysia and Cambodia immigration, and not Thailand.

>i was planning to go kou samui-KL and stay hotel in airport and back to thailand within 24hours

If you want a new visa, it'll take at least two business days - one to drop off your passport, and the next day to pick it up. If you are doing a border bounce, I suppose your plan can work. But this isn't a travel advice group.

I'm assuming you have a multiple entry Non-B, and you want another 90 day stamp?