Abstract: An intelligent monitoring system for drilling water level based on Narrow-band Internet of Things is designed. The system controls the forward and reverse rotation of the DC motor through the intelligent telemeter, drives the capacitive water level switch to detect the water surface position, the rotary encoder records the falling distance of the capacitive water level switch, and processes the rotary encoder data through the low-power microprocessor STM32F103RCT6 to obtain the water level data. Then, the Narrow-band Internet of Things technology is used to transmit the water level data to the China Mobile Internet of Things open platform OneNET through the mobile cellular network, and the monitoring computer accesses the OneNET platform water level data through Ethernet to realize the wireless real-time monitoring and early warning function of the drilling water level.