The utility model discloses a power plant draught fan end cap spanner which solves the problem that a person has difficulty in disassembling a draught fan end cap on the spot because of limited space. The power plant draught fan end cap spanner comprises a spanner handle (1). An inverted-triangle-shaped spanner head (2) is arranged at the top end of the spanner handle (1); cylindrical spanner claws (3) are fixedly arranged on three vertexes of the inverted-triangle-shaped spanner head (2). A hollow hole (4) is formed in the center of the inverted-triangle-shaped spanner head (2). The power plant draught fan end cap spanner is easy to manufacture, convenient to use and particularly suitable for on-the-spot use.