Online and offline teaching mode is a novel teaching mode which meets the requirement of the development of modern society, especially due to the emergency affect by the COVID-19 pandemic this year. This novel teaching mode integrates "online teaching" and "offline teaching", which has played a good role in promoting the high-quality teaching-learning experience and demonstrated the advantageous teaching-learning effect. Based on the analysis of existing problems, several specific instructional strategies are presented to improve the online and offline teaching, including making emergency teaching plan to prevent emergencies, emphasizing deep-level communication in online teaching not only voice, making comprehensive online platform resources, and Integrating offline and online teaching-learning.