A transformer structure with a guiding and positioning device and preventing power failure, comprising a compartment device (9) having a square cross-section for installing a transformer (1), and an inclined surface guide frame assembly installed in the compartment device (9) (91) and positioning engagement means (3) for securing with said transformer (1) by means of fasteners (30), said inclined surface guide frame assembly (91) comprising means for being hingedly mounted on said compartments, respectively (9) Four inclined guide frames on the corner plate (913) fixed at the four corner positions, each inclined guide frame includes a hinge (914) and the corner plate (913) A hinged rotating arm part (911) and a sloped part (912) fixedly connected with the rotating arm part (911) and inclined outward from bottom to top; the positioning and engaging device (3) includes a square roller support frame ( 32).