The blaze began in the morning at the home in the province's Lankao County, Xinhua News Agency reported. A county official said it took about 2 hours to contain it.
It was not immediately known how many children were at the facility when the fire started. Firefighters said four children died at the scene and other three died while being taken to a hospital.
Another child was injured and was undergoing treatment.
Local residents were quoted as saying a woman in the home was using the place to shelter orphans and abandoned children.
There were no other details about the orphanage or the woman. The cause of the fire was being investigated.