This paper establishes a long-term growth forecast model for domestic and inbound tourism demand of 11 cities in Guangdong-Hong Kong-Macao Greater Bay Area by using econometric methods，and analyzes the possible impact of COVID-19 epidemic on tourism demand. The prediction and evaluation results show that the tourism demand of Greater Bay Area cities is expected to drop sharply due to the impact of the epidemic in 2020，but it is expected to rebound significantly in 2021；The decline of inbound tourism demand is generally greater than that of domestic tourism demand. The evaluation of the impact of the epidemic and the recovery trend of tourism demand provides a theoretical and empirical reference for the formulation of policies to cope with the epidemic and promote the recovery of tourism industry in Greater Bay Area.