Existing wireless data transmission modules have some disadvantages, such as high power consumption, short transmission distance, low reliability and high cost. In this paper, a new design of wireless data transmission module based on LoRa was proposed. The module uses SX1276 as the radio frequency chip and the low-power microprocessor STM8L151 as the main chip, and embeds the contiki operating system. We discuss the design of hardware and software in this module, and evaluate its performance. The final tests indicate that the proposed wireless transmission module has advantages of low power consumption, long transmission distance and high reliability. It is suitable for use in wireless meter reading and environmental monitoring systems.