Complex problem solving is recognized as an important resource of empirical knowledge accumulation. Learners can acquire and consolidate their empirical knowledge based on practical experience in the complex problem solving. Although many studies on complex problem solving have documented the effects of problem solving on knowledge accumulation, few have addressed the detailed process of empirical knowledge accumulation in the complex problem solving. The purpose of this study is to explore the process of novices' empirical knowledge accumulation in solving complex problem. A multi-stage experiment based on a real-world engineering problem is presented in the study. By means of analysis of the difference between novice and experts, a novel concept of “inflection point” and a novel “four period novices' empirical knowledge accumulation curve” are presented, which can be used to explain the novices' empirical knowledge accumulation process in solving complex problem.