The invention discloses a substation oil-filling equipment oil leakage rate monitoring system. A piezoelectric droplet measuring sensor collects oil drop dropping information when an oil drop at an oil leakage point passes through a sensor setting region; the oil drop dropping information is collected by an analog quantity AD interface and is input to a single-chip microcomputer; a lithium battery is adopted to supply power; and when the dropping speed is higher than a certain set value, leakage rate is calculated after circuit processing and single-chip microcomputer processing, and the leakage rate is sent to a set mobile phone through a GSM module in the form of a short message, thereby facilitating to carry out real-time tracking on the leakage trend, helping operation and management personnel of a substation to know the oil leak information of the oil leakage point in time so as to make decisions and take effective measures in time, and preventing the trouble of long-term repeated patrol of the operation and management personnel of the substation.