"What is your model?" is correct English, but probably not what you intended. The word "model" could refer to a way of doing something: "Lacking the ability to mass produce shoes, the cobbler was unable to adapt to the new model that was taking over." (Note: be careful not to confuse "adapt to", which means to change, with "adopt", which means to follow) "model" could also mean one's mathematical, abstract, philosophical, or other representation of something: "You will discover that my model for population growth is quite thorough thanks to Microsoft Excel." However, you probably didn't mean either! You really meant to ask: "WHO is your model? This is ambiguous. It could mean "Who is the supermodel that you're dating?" Mostly likely, you are referring to a "role model", in which case, Helene's comment has your answer: "Who is your role model?"

What on earth do you mean?