If I cook velveeta cheese in a crockpot on high for four hours will it burn

I don't think it will burn, but I would check it after 2.5 hours and every 30 minutes after that. I've seen similar sounding recipes and while I have not tried them, 6-7 hours on low or 3-4 on high is fairly typical.

It seems odd that broccoli and rice casserole would cook for FOUR hours on HIGH. Is the cheese is just a component of the casserole? I would re-evaluate the temperature for such a long time for all the ingredients listed. Is this a recipe you have made before? Doesn't sound too accurate to me...

Kayla: Does your crock pot have to be on high? What is your final goal in velveeta texture?

I don't know about burning, but it might disintegrate. Why would you want to do that?

That seems aggressive! I don't have the personal experience to back it up, but if you're heating over that long a time frame, I'd suggest a lower heat.