Field water surface sensing device, system and method

The invention provides a field workmanship water sensing device, system and method. The sensing device comprises: a conductivity ruler which is provided with at least one detection point, wherein the at least one detection point is provided with a conductivity electrode group; a circuit unit electrically connected with the conductivity ruler to provide voltage and/or current signals for the conductivity ruler and receive detection signals from the conductivity ruler; and a power supply unit module electrically connected with the circuit unit to provide a required power supply. The invention also provides a field sensing system. The system comprises a cloud server, at least one field water-workmanship sensing device and a remote monitoring platform server. Therefore, the paddy field water depth and specific conductivity can be monitored in real time to achieve the effects of optimizing water resource utilization, saving paddy field water consumption, reducing plant loss rate, managing paddy field fertilizer ap