Abstract: Total health expenditure is an important index to evaluate the health investment level and fund utilization status of a country or region. Based on the data of Shanghai Statistical Yearbook from 2005 to 2018, ARIMA model and GREY GM (1.1) model were used to forecast and analyze the development trend of total health expenditure and its proportion in GDP in Shanghai. The study found that the total health expenditure and its proportion in GDP of Shanghai will continue to grow steadily from 2018 to 2025. The forecast results show that the total health expenditure and its proportion in GDP of Shanghai will reach 476.519 billion yuan, 597.659 billion yuan, 8.53% and 10.21% respectively in 2025. The average relative errors of the established ARIMA model and the grey GM (1.1) model are both less than 10%, and the fitting degree is good and the prediction accuracy is high, but the grey GM (1.1) model is better than the ARIMA model. The paper puts forward that Shanghai should control the reasonable increase of the total health expenditure on the basis of keeping the investment. We will maintain proper matching between health expenditure and the level of economic development, improve health efficiency, and provide people with higher quality, more inclusive and more efficient health services.