You need to determine who is publishing books that are similar to yours. You could ask an expert. In any community there is likely to be someone extremely knowledgeable about children's literature. They could be a librarian, a college professor, or the owner of a children's book store. Try to stay focused on what's been published recently.
Trends change and so do editors.
The internet is another way to find such publishers. You can sit at your computer and try key word searches. Many publishers have websites that will yield all kinds of useful information. Some even have e-mail links enabling you to ask questions about their offerings. There are also chat groups, list serves, and online newsletters that offer you the opportunity to network within the children's literature community.