The invention belongs to the technical field of enterprise wastewater management, and particularly relates to an enterprise discharged wastewater monitoring system and monitoring method. The system comprises a monitoring unit, a monitoring platform and a mobile terminal, wherein the monitoring unit comprises a flow detector, a camera, a first GPRS positioning module, a valve control module, a characteristic factor detector, a reserved sample collector and a first remote transmission module, wherein the first remote transmission module is connected with the flow detector, the camera, the firstGPRS positioning module, the valve control module, the characteristic factor detector and the reserved sample collector; and the monitoring platform comprises a processing operation unit, a data generation unit, an early warning unit, a second remote transmission module and a display unit. According to the invention, closed-loop management of real-time calling of monitoring data, timely processingof early warning and alarm, real-time distribution of law enforcement work orders, enterprise emission monitoring, alarm processing and processing result feedback tracking can be realized, and the supervision law enforcement efficiency, the enterprise governance level and the ecological environment quality are comprehensively improved.