The utility model discloses a rotating platform for excavator, including little otic placode, big otic placode, right side girder, preceding bent plate and upper cover plate and swing arm round pin shaft hole, big otic placode is hugged closely the welding with the right side girder and is set up, and little otic placode is hugged closely the welding with big otic placode and is set up, little otic placode, big otic placode and right side girder weld the setting in proper order, and are provided with swing arm round pin shaft hole on little otic placode, big otic placode and the right side girder stitch welding layer, lie in one side that the right side girder is inboard, be provided with little otic placode and big otic placode simultaneously, preceding bent plate sets up with big otic placode vertical?welding, and little otic placode only lie in before bent plate one side, and big otic placode all has the distribution in the both sides of bent plate in the front, wherein the upper cover plate overlap joint on big otic placode and the right side girder is extended to bent plate one side in the past. Through improving big otic placode structure, bent plate opposite side before extending to it to form the overlap joint with the upper cover plate on the girder of right side, strengthen the position of right side girder fracture, solve the problem of girder fatigue cracking, and then improve rotating platform's life.