The popularity and development of electronic payment instruments changed people’s life, it challenges the traditional finance theory while. In this paper,we derive the monetary multiplier formula first,and then select the sample data of China’s payment instruments to set up an econometric model. We test the correlation of electronic payment instruments and monetary multiplier, find that electronic payment instruments expand monetary multiplier and accelerate the implementation of monetary multiplier. So the timeliness of the central bank’s monetary policy that controls the base money to control liquidity will be strengthen, we should estimate it adequately.