Walking planetary reducer of mining excavator

The invention provides a walking planetary reducer of a mining excavator, which relates to a mining excavator. The invention solves the problems of low carrying capacity and inconvenient maintenance of the walking planetary reducer in the prior art. The invention is characterized in that a first-level input gear shaft is meshed with a gear, the gear is connected with a second-level sun shaft by adopting a spline, a second-level planetary wheel and a second-level internal gear ring are driven to be meshed by the second-level sun shaft, the second-level sun shaft is used for driving a second-level planetary frame to integrally rotate through the connection of the second-level planetary wheel and a pin shaft (1), the second-level planetary frame is connected with a third-level sun shaft in a tooth mode, a third-level planetary wheel and a third-level internal gear ring are driven to be meshed by the third-level sun shaft, the third-level sun shaft is used for driving a third-level planetary frame to form a third-level planetary transmission mechanism through the connection of the third-level planetary wheel and a pin shaft (2), and finally, the third-level planetary frame is used for outputting a twisting moment through an internal spline.