The utility model relates to protection equipment for a farmland field water-saving irrigation monitoring system, in particular to a field soil moisture monitoring well. The field soil moisture monitoring well comprises a well cover, a shaft and an instrument tray, wherein the shaft is buried in a monitored field; the top of the shaft is connected with the well cover; the instrument tray for placing monitoring equipment is arranged in the shaft; and a plurality of sensors are buried in the soil under the instrument tray and respectively are connected with the monitoring equipment through the instrument tray. The field soil moisture monitoring well has a well-type structure, is arranged in wild filed and can operate under the unattended condition throughout the year; and moreover, the occupied field space is small and an additional space does not needed during the monitoring operation; and therefore, the field soil moisture monitoring well is simple in structure and high in protection effect, and cannot be influenced by climates.