China's economy has unique characteristics that have led to fluctuations in economic growth. By analyzing data from 1978 to 2018, it was found that China's economy is more volatile than developed countries, with consumption being more volatile than output. Institutional reforms have played a significant role in China's economic growth, impacting trend fluctuations and cyclical fluctuations. A model was constructed to show that these institutional changes have caused China's economic fluctuations to be greater than those of developed countries.