The invention discloses a distributed farm monitoring system based on NB-IoT. The distributed farm monitoring system based on the NB-IoT comprises a sensor network, a valve network, a cloud server anda remote terminal. The sensor network comprises a plurality of sensor nodes distributed in areas of a farm, the sensor nodes comprise first microprocessors, sensors and first NB-IoT modules, whereinthe sensors and the first NB-IoT modules are electrically connected with the first microprocessors, and information collected by the sensors is controlled by the first microprocessors to transfer to the cloud server through the first NB-IoT modules. The valve network comprises a plurality of watering device nodes and slide rail motor nodes, the watering device nodes comprise second microprocessors, watering device valves, second NB-IoT modules, watering devices and water pipes, wherein the watering device valves and the second NB-IoT modules are electrically connected with the second microprocessors, the watering devices are connected with the watering device nodes, and the water pipes are connected with the watering devices. The slide rail motor nodes comprise third microprocessors, thirdNB-IoT modules, slide rail motor valves, slide rail motors and pulleys, wherein the third NB-IoT modules, the slide rail motor valves and the slide rail motors are electrically connected with the third microprocessors, and the pulleys are electrically connected with the slide rail motors. The distributed farm monitoring system based on the NB-IoT has low cost and power consumption, and users canconveniently manage the farm remotely.