The interaction between light and nanostructures has always been one of the important topic in nanophotonics. The nanostructure of the core components play an important role in the function and performance of photonic devices. There are two approaches in the design of nanophotonic devices. One is based on physical principles and intuitive

while the other employs the idea of inverse design to obtain the optimal structure according to the required optical response. In recent years

inverse design has made great progress in nanophotonic devices. In particular

the technology of deep learning was recently introduced

promising for the design of high-performance nanophotonic devices. This article focuses on inverse design method of the nanophotonic devices. The background

key progress and typical applications of this emerging research direction are analyzed and summarized

and the challenges and prospect of inverse design are also presented.