The invention relates to a dust detection device, a dust reduction spray device and a system for construction site environment control, including a dust detection smart sensor, a dust reduction spray control smart sensor, and a background management system connected with the dust detection smart sensor and the dust reduction spray control smart sensor , The background management system provides data collection management, middleware management, data fusion management, and distributed management, and realizes the functions of environmental dust detection, sound and light linkage, dust reduction and spray linkage, and intelligent early warning. Based on intelligent sensing equipment, the system has flexible installation, real-time detection, multi-terminal display, timely linkage, voice reminder, and high reusability; it is installed in key dust control areas to ensure that the construction site meets the dust control requirements, improve the quality of on-site construction, and strengthen And improve the engineering quality and safety management of the construction industry.