The invention provides a method for judging the type of low-frequency oscillation. The method comprises the steps of setting a sliding window and an oscillation energy threshold value; calculating oscillation energy of a unit in each time period, and determining a target unit; calculating an oscillation energy spatial distribution entropy and per unit standard deviation indicator of the target unit in each time period; calculating an entropy difference classification indicator according to the oscillation energy spatial distribution entropy and the per unit standard deviation indicator of the target unit; and judging the type of the low-frequency oscillation according to the entropy difference classification indicator. The technical scheme provided by the invention discloses motion characteristics of the low-frequency oscillation in nature, visually reflects difference characteristics of different types of low-frequency oscillation, is more obvious in adaptability and differentiation effect, and proposes the per unit standard deviation indicator to reflect the percentage taken by oscillation energy of the unit; and energy distribution characteristics of different types of low-frequency oscillation are comprehensively represented according to an entropy difference classification criterion, the changing trend of oscillation energy along the time is reflected by using the sliding window, and thus different types of low-frequency oscillation is differentiated accurately and effectively.