To ensure the smooth operation of the zero liquid discharge system in steel industry, the stable performance of the key apparatus, mechanical vapor recompression (MVR) system, is one of the critical factors. During the operation of MVR, issues such as scaling and blockages frequently arise during the stages of preheating in two-stage (or three-stage) plate heat exchangers, heating in shell and tube heat exchangers, and crystallization in crystallizers. These issues necessitate frequent chemical cleaning or manual physical cleaning, which affects the stable operation of the MVR system. This study, through the analysis and summarization of common scaling locations and types in actual engineering cases, identifies several aspects: The direct impact of variations in ion concentration in the feed liquid on scaling rate and quality, the distinct relationships between two types of scaling calcium sulfate and calcium carbonate and temperature, the influence of heat transfer velocity per unit heat exchange area on ion scaling rate, three-dimensional fluorescence spectroscopic analysis of organic components in the feed liquid, and the selection criteria for scale inhibitors under high-temperature conditions. Targeted countermeasures are also proposed. By controlling these key factors, the scaling issues can be effectively reduced, offering a reference for the commissioning and operation of MVR, thereby enhancing the operational efficiency and reliability of zero liquid discharge (ZLD) system and advancing the development of wastewater treatment technologies in the steel industry.