If I have a PPO against my kid’s father for domestic violence, is he allowed to see our children?

You need to take a look at the PPO and the language in the document to see if the kids are mentioned. If the PPO is just for you, then the kids should be allowed to see their father. There are organizations that work with Child Protective Services that can help arrange visits for the children so that neither of you have to worry about violating the PPO.

I would have to see the PPO in order to be able to render an opinion. Generally if they PPO is solely directed at yourself, then he would be able to have parenting time with the children as long as it was done in such a manner as to not violate the PPO.