The utility model discloses a portable electric power warning sign, including four spinal branch vaulting poles with set up the first mounting panel at the bracing piece top, first mounting panel top is provided with the protection casing, at the fixed motor in first mounting panel middle part, the output shaft of motor extends to the below of first mounting panel and is connected with a triangle mounting bracket, the triangle mounting bracket be positive triangular prism shape frame construction, the three side end face of triangle mounting bracket all is fixed with the installation panel, the inboard of installing the panel is passed through the link and is connected with the fixed axle, the fixed axle and the output shaft fixed connection of motor, all the laminating is provided with the signboard on three installation panel, lower extreme at four spinal branch vaulting poles is equipped with the second mounting panel, is provided with the UPS power on the second mounting panel, the UPS power -on cross the circuit with the motor connect. The utility model discloses a prismatic sign warning structure of going of design triangle cooperates the motor rotation to make the warning dynamics greatly increased of warning sign, through setting up the stable work that UPS power structure had guaranteed the warning sign.