In the post-pandemic period of COVID-19, the majority of cities in China try to balance the normalization of epidemic prevention and social-economic development. However, the appearance of asymptomatic infected patients poses threats to public health, which might be infectious without clinical symptoms and only be detected by testing approaches. Along with the appearance of one symptomatic case, a regional large-scale screening program was carried out in Shenzhen City charged by a regionally integrated healthcare system. The large-scale screening contributed to preventing epidemic transmission. The integrated healthcare system coordinating regional medical institutions and optimizing regional medical recourse had advantages to address public health emergencies.