With the gradual upgradation of global energy consumption and the associated development of multi-energy sources, the pace of unified energy planning and design has been accelerated and the concept of multi-energy system (MES) has been formed. The industrial structure of industrial park (IP) consists of production and marketing of multi-energy sources, which makes IP become an ideal application scenario for MES. The coupling between multi-sources raises the complexity level of IP, which requires the demand side analysis in IP as it enables customers to actively participate in energy planning and development. This paper presents the concept and operation strategies of integrated demand response (IDR), and its model classification is analyzed in detail. Optimization model and IDR with varying time period are studied in IP to determine their impacts on the system. A detailed survey of different techniques in both operation strategies and model classification is presented and the classification is based on pros and cons. Finally, key issues and outlooks are discussed.