The invention discloses an on-line monitoring device of an equipment working condition. The on-line monitoring device comprises a special-purpose measuring instruction for measuring mountain torrent and disaster data of a monitoring station, an environmental measuring instrument for collecting working condition data of the special-purpose measuring instruction, a microprocessor for processing the mountain torrent and disaster data measured by the special-purpose measuring instruction, and a communication module for communicating with a server side. Besides, the microprocessor is also used for processing the working condition data of the special-purpose measuring instruction; and the communication module is also used for sending the processed working condition data of the special-purpose measuring instruction and mountain torrent and disaster data to the server side. According to the on-line monitoring device provided by the invention, the working condition data of the special-purpose measuring instruction are obtained, the state of the special-purpose measuring instruction of the monitoring station is determined in advance based on the working condition data, and overall arrangement is carried out on the operation and maintenance, so that the operation and maintenance costs are lowered, the operation and maintenance cycle is reduced, and the accuracy of the monitoring data of the monitoring station is enhanced and thus the property security of people is guaranteed directly.