Abstract: In view of the special and precision of the generator structure, it is necessary to prevent the metal foreign matter left in the generator, otherwise it will cause wear in the generator chamber, short circuit, breakdown and ground trip 1. When the generator is disassembly and maintenance, the interior is exposed to the outside world, because there is no suitable shelter, there is a foreign body falling into the chamber, especially in the knocking operation, turbine disk rotation, there is a risk of breakage or tool metal and other foreign body ejection into the generator chamber. Based on long-term accumulated maintenance experience, this paper improves the maintenance end protection technology, designs and develops a generator maintenance end protection cover, realizes the protection and isolation operation during the maintenance of the generator, and improves the quality and efficiency of the maintenance of the generator. The protective cover is based on the large end cover by size and structure, respectively, the upper protective cover and the lower polypropylene waterproof cloth two parts, removable, can be used for the rotor in the chamber and outside the chamber two protection modes, can solve the traditional generator disassembly process without measures to prevent foreign matter falling into the risk of foreign matter falling into the problem of constraints in operation steps, greatly improve the safety and work efficiency of generator maintenance. Change the past all rely on personal experience ability to guarantee the quality of maintenance, to ensure that in the case of isolation protection and safe and fast completion of generator end maintenance operations.