The utility model discloses a maintenance warning board for secondary equipment in a transformer station, and solves the problem that time and labor are wasted and insecurity is caused because in the prior art, running equipment in maintenance screening cabinets and adjacent screening cabinets are covered with red curtains. The maintenance warning board comprises a telescopic scroll box (2) and a prompt curtain (4), wherein the upper end of the prompt curtain (4) is fixedly connected with scrolls in the telescopic scroll box (2); a pull rod (3) is arranged at the lower end of the prompt curtain (4); and a hook (1) is arranged on the telescopic scroll box (2). The maintenance warning board is particularly suitable for maintaining secondary equipment in the transformer station.