In today's increasingly modernized and globalized world, people are paying more attention to and cherishing cultural heritage. With the innovation and development of technology, modern digital technology begins to provide new ways of information collection, preservation, transformation and dissemination for cultural heritage. Laosicheng is the largest Tusi cultural relic in Southwest China and one of the world cultural heritages of China. However, with the passage of time, Laosicheng is facing the danger of disappearing. The goal of this study is to use digital technology to protect and disseminate the cultural heritage of Laosicheng in China. The research discussed the value of the cultural heritage of Laosicheng, the main problems currently faced, and what new and effective digital technologies can be used to protect and disseminate the cultural heritage of Laosicheng. In an actual case, this study uses digital technology to vividly and intuitively display the cultural heritage of Laosicheng to the whole country and even the world, reinterpret and interpret the cultural heritage, and endow it with new cultural and era connotation. It is hoped that this study will inspire people, especially the new generation, to learn to adopt new technologies to promote the excellent cultural heritage, and eventually realize the comprehensive utilization and sustainable development of cultural heritage.