The utility model provides a trend power generation system maintains device, including floating floating platform, dead axle and slide mechanism, floating floating platform and floating on the surface of water, its bottom is connected the top of dead axle, the slide mechanism link bit is used for following in underwater trend power generation system's power generation facility the dead axle slides and the pulling power generation facility, when when power generation facility need maintain or maintain, utilize slide mechanism follows it it rises to nearly surface of water position to decide axial tension. The utility model discloses a control slide mechanism bears power generation facility and follows reciprocating of dead axle, will treat that the power generation facility of maintenance maintains by transferring to nearly surface of water department under water, not only reduces maintenance?work's complexity, has reduced the operation degree of difficulty moreover to the potential safety hazard that maintenance person person carries out underwater maintenance has been reduced.