The invention discloses an electric power day-ahead market match trade method with a power grid safety constraint embedded therein, and belongs to the technical field of electric power market trade. The method comprises obtaining electric power market bid basic data, constructing an electric power market match trade mathematical model with the power grid safety constrain embedded therein according to the data and obtaining a trade result through calculation by use of a linear programming solver. The method provided by the invention brings forward a novel object function of the electric power market match trade mathematical model, demonstrates a match trade high-low coupling principle and can obtain the trade result comprising match trade matched-pair information; and a line active transmission limit constraint is embedded into the electric power market match trade model for unified optimization so that the trade result satisfying the power grid safety constraint can be obtained. The method provided by the invention can provide key technical support for an electric power day-ahead market applying match trade, solves the problem of consideration of embedding the power grid safety constraint into the electric power day-ahead market and improves the safety of the trade result of the electric power day-ahead market.