Aiming at the problem that single-core CPU needs to process multiple tasks at the same time,considering the multi-task management requirements of bicycle odometer with STM32 F4 single-core processor as the core,the FreeRTOS operating system is used to realize the data measurement task,LCD display task and two timer task of bicycle odometer.The results show that the bicycle odometer can effec-tively calculate and display the speed and mileage of the bicycle in the LCD,and has good interactivity.