The invention relates to environmental monitoring and discloses an automatic monitoring system for working conditions of a pollution source discharging process. The automatic monitoring system comprises a server and a plurality of acquisition terminals connected with the server through network cables. Each acquisition terminal comprises a microprocessor, a network communication module, a storage and a data acquisition terminal interface, the network communication module, the storage and the data acquisition terminal interface are electrically connected with the microprocessor, and the data acquisition terminal interface is connected with at least one sensor. The invention further discloses a monitoring method using the monitoring system. The monitoring method includes the steps of firstly, transmitting data acquisition commands at intervals by the server through a network; secondly, acquiring data by the acquisition terminals; thirdly, recognizing the commands by the acquisition terminals; fourthly, reporting data; and fifthly, receiving data. The automatic monitoring system and the monitoring method has the advantages that the problem limited port numbers of traditional center end data platform is solved, networking is simple, flexible, and convenient, and the automatic monitoring system is available for unit operation and networked operation.