This paper describes the design and implementation of a wireless sensor based on NB-IoT (Narrow Band Internet of Things) for monitoring agricultural environmental information. The sensor is capable of real-time monitoring of four environmental parameters, including ambient temperature, relative humidity, illuminance, and CO2 concentration. In the hardware design, sensor elements are selected based on the measurement ranges and accuracies specified in agricultural environmental monitoring industry standards. The hardware circuit is designed using the BC35-G type NB-IoT module and STM32 MCU (Microcontroller Unit). In the software design, data from the environmental parameters are collected and processed by the STM32 MCU and sent to the OneNET cloud platform through the NB-IoT module. The OneNET cloud platform enables users to view the relevant environmental data collected by the sensors using mobile phones and other mobile terminals. To test the effectiveness of the developed sensors, they were tested in a glass greenhouse at Fuyang Ziqing Agricultural Technology Co., Ltd. in Anhui Province. The results demonstrate that the sensors
can accurately collect the data of relevant environmental parameters and can provide stable wireless transmission of data remotely, making them suitable for practical engineering applications. In summary, this wireless remote monitoring sensor based on NB-IoT represents a significant advancement in the field of agricultural automation. The sensor's ability to accurately monitor and wirelessly transmit data in real-time provides farmers with valuable information to optimize crop growth and maximize yields.