In order to prevent cracks and improve the construction quality of mass concrete, an intelligent monitoring and control system for crack prevention of mass concrete was developed. The system is composed of four parts, including those relating to perception, interconnection, analysis and decision making, and control, and can realize automatic perception, transmission, interconnection, and sharing of temperature control information throughout the processes of raw material precooling, concrete mixing, transportation, placement, spreading, and vibration, water cooling, and concrete surface maintenance, as well as partly intelligent control of these processes. The system has also realized management of all factors and the entire process of temperature control and crack prevention based on network technologies and the internet of things. Applications show that the system can help improve the managment level and prevent cracks during concrete construction through automatic acquisition of information, accurate control, real-time evaluation, intelligent intervention, and decision making support during the implementation of field temperature control.