According to the accuracy requirements within ± 0.1mm of the clapboard paper length, we designed an automatic battery package machine clapboard paper control system based on STM32F103 micro-controller. We choose a two-phase hybrid stepper motor as the main action element of the design, and choose STM32F103 micro-controller based stepper motor micro-stepping method to meet the accuracy requirements. With the IO port of timer in the MCU, output SPWM waveform current to control two H-bridge circuit, and drive the stepper motor. This design has the following advantages: paper fill speed and paper length can be controlled, and high precision, high reliability stably operate.