Foundation pit wireless monitoring and alarming device and monitoring method

The invention discloses a foundation pit wireless monitoring and alarming device and a foundation pit wireless monitoring and alarming device-based monitoring method, which relate to the technical field of geotechnical engineering, in particular to the technical field of wireless automatic monitoring and alarming systems for foundation pit engineering. The foundation pit wireless monitoring and alarming device comprises a plurality of ordinary monitoring sensors, a data acquirer, an expander, a computer and an alarming device, wherein the signal output ends of the ordinary monitoring sensors are connected with the signal receiving end of the data acquirer; the signal output end of the data acquirer is connected with the signal input end of the expander; the signal output end of the expander is connected with the signal input end of the computer; and the signal output end of the computer is connected with the signal input end of the alarming device. The device and the method fulfill the aims of automatic real-time monitoring, simple structure and low cost, and are convenient to use.