The invention discloses a forecasting method and a device of telephone traffic in an ordinary holiday of a telecommunication network, wherein the method comprises the following steps: acquiring the history value of telephone traffic of the network as history sample data, pre-processing the history sample data and obtaining normal sample data; carrying out modeling and forecasting on the normal sample data by utilizing a forecasting model; utilizing a variance analysis method to carry out a significance test of difference of the telephone traffic in holidays and the telephone traffic at ordinary time on the normal sample data; if the difference of the telephone traffic in holidays and the telephone traffic at ordinary time is significant, carrying out correction on forecasting values of the forecasting model and obtaining a final forecasting value; or the forecasting value of the forecasting model is the final forecasting value. The invention also discloses a forecasting device of telephone traffic in an ordinary holiday telecommunication network, so the invention can carry out accurate forecasting on the telephone traffic in the ordinary holiday.