After an in-depth study on the report made by Xi Jinping in the 19th National Congress of CPC, on the basis of the investigation of 12 financial crises since the 20th century, this paper makes a study on the causes of systematic financial risk. Combined with the situation facing the current systematic financial risk in our country, this paper also puts forward some countermeasures to prevent systematic financial risk. Studies suggest that the systematic financial risk in China is very serious after a comparative study between the cause of systematic financial risk leading to financial crisis in the past 100 years and the current financial situation in China. Therefore, some relevant policies should be taken, under the leadership of the Party, to prevent the happening of systematic financial risk, such as fighting financial corruption, appropriately tightening monetary policy, perfecting the financial regulatory system, maintaining currency value stability, strengthening supervision of financial science and technology, etc.