Slewing bearing mounting system and excavator

The utility model provides a pivotal bearing mounting system and an excavator, and relates to the technical field of excavators. The pivotal bearing installation system comprises a main frame, a pivotal bearing, a pivotal bearing support and a fixed bottom plate, the pivotal bearing is connected with the main frame and the pivotal bearing support, the pivotal bearing support is further connected with the fixed bottom plate, the pivotal bearing support comprises a support cover plate and a support fixing sleeve, and the support cover plate is fixedly connected with the fixed bottom plate. The support cover plate and the support fixing sleeve are integrally formed; the slewing bearing comprises an inner ring and an outer ring, the support fixing sleeve is sleeved outside the outer ring and is detachably connected with the outer ring, and the inner ring is arranged on the support cover plate and is detachably connected with the support cover plate. According to the technical scheme, the problem that spot welding