Abstract: The park integrated energy system can significantly improve its operation economy through multi-energy complementary. However, the uncertainty of the controllable resource response will bring challenges to the formulation of the day-ahead dispatching strategy. Thus, a day-ahead optimal economic dispatching strategy considering the integrated demand response and its uncertainty is proposed for the park integrated energy system. Firstly, the uncertainty of photovoltaic and load forecast power and the uncertainty of flexible load response are described by triangular fuzzy number, and a day-ahead dispatching model considering uncertainty is established. Then, in order to minimize the total operation cost of the system, the controllable resources of the supply and demand sides of the system are optimized. According to the fuzzy scheduling theory, fuzzy expectation constraints and fuzzy chance constraints are equivalently converted into their certainty forms for easy solution. Finally, the case analysis shows that the proposed strategy can further reduce the operating cost through integrated demand response; and the impact of fuzzy chance constraint confidence level on the system operating cost is analyzed.