The invention discloses a solar proton event peak flux prediction method, and relates to the technical field of proton events, and the method comprises the following steps: S1, obtaining solar high-energy proton data in real time; s2, obtaining an energy spectrum factor Ri according to an energy spectrum factor calculation formula; s3, according to a relational expression lg (Ri) = C + D * F10 of the energy spectrum factor Ri and F10, obtaining constants C and D by using a least square method, and meanwhile, obtaining a correlation coefficient rr according to a correlation coefficient calculation formula; s4, calculating a predicted value F10max of the maximum value of the proton event according to a predicted value formula F10max = (lg (Rmin)-C)/D of the maximum value of the proton event, S5, repeating the steps S1-S4 to obtain predicted values of the maximum values of a plurality of proton events, calculating an average value of the predicted values of the maximum values of X continuous proton events when a relative error between the predicted values of the maximum values of the X continuous proton events is smaller than P, and if the relative error between the predicted values of the maximum values of the X continuous proton events is smaller than P, calculating the average value of the predicted values of the maximum values of the X continuous proton events. Therefore, the prediction value of the peak flux of the proton event is calculated.