A high-performance Narrow Band Internet of Things (NB-IoT) wireless street lamp controller is designed in this article. The wireless communication module of this street lamp controller is achieved by using the NB-IoT transmission module M5311, and the embedded single-chip STM8 is taken as the controller. Electrical parameters such as voltage, current, power, electrical energy, and power factor of street lamps can be measured in real time by the intelligent electrical energy collection chip HLW8112 in the designed street lamp controller, which has the functions of lamp fault diagnosis and alarm, remote or local gradation and instant dimming of lamps, power switch control and so on. The interface circuit between M5311 and CPU, D/A dimming circuit and electrical parameters acquisition circuit of wireless street lamp controller, the main program, timer interrupt service subroutine, networking service subroutine, instruction analysis subroutine, fault diagnosis subroutine of the control program and communication protocol between street lamp controller and remote control platform are analyzed and designed. The experimental results of the street lamp controller test platform verify the functions and performance of the NB-IoT wireless street lamp controller, which can meet the requirements of modern urban street lamp intelligent control.