Intelligent photonic processing system (IPS) combines artificial intelligence (AI) technology and photonic technology to achieve intelligent, high-speed, large-bandwidth and high-performance signal processing. IPS mainly includes AI-powered multifunctional photonic processing system, intelligence signal processing with photonics-facilitated AI and neuromorphic photonic processing system. In this article, the concept of IPS is briefly introduced first,then the research progresses of our resaerch group in the AI-powered multifunctional photonic processing system are described, and further the development trends and necessity of explainable AI are discussed. And the research of our group on the explainable AI-powered multifunctional photonic processing system is introduced.