It sounds like there needs to be some adult intervention. In having a pet and a child, you need to make the adjustments and take the time to train both, properly.
Teach the child to respect the dog. Teach the child to only pet the dog, if the dog wants to be petted. Teach the child to approach the dog, gently and not by force. Teach the child to speak softly to the dog. Teach the child the signs a dog gives when it is not in the mood for interaction. These are all things a child can learn.
Teach the dog to sit. Teach the dog it is O.K. to be petted, gently. Teach the dog that the child can walk it on a leash, with the ADULT THERE. Teach the dog he can go to his own dog cage for a safe place where NO ONE WILL BOTHER HIM.
If a child is overwhelming a dog, the dog may make this mistake. If the child continues to do this, the unfortunate issues may be that the dog might develop continuing habits of protecting himself due to lack of parental intervention.
If you cannot teach both, properly, then take the dog to an animal rescue league. Do not say the dog is a “biter”. Simply state you do not have time to train both a dog and a child. That is enough for the league to know what to do. You can inquire with your local pet supply store for animal rescue league contacts.
DO NOT take the dog to the shelter and DO NOT say the dog is biting your child.
I have to say – in looking at your other questions, you sound like a teenager and probably don’t have a dog? Or a child?