TRIZ innovative thinking method, as an invention problem-solving theory, can assist technicians in invention and innovation. Among them, 40 invention methods are one of the most commonly used innovation tools,which has been applied in many industries and achieved good innovation results. Through the research on the 36th invention principle of 40 invention methods - phase change principle, its transformation process among gas phase, liquid phase and solid phase is analyzed , as well as various applications in food production, processing, packaging and transportation, hoping to provide theoretical reference for the practice of invention principle and further promote the application of TRIZ method in food innovation.