A robot integrated joint unit and a legged robot applying same are related to the technical field of robot joints. The robot integrated joint unit comprises a first electric motor and reducer assembly, a second electric motor assembly, a second reducer assembly, and a first output connecting rod. Two motors of two joints are disposed on a same side of the joints, thus preventing the need for electric motor power cables to run through the joints, effectively alleviating fatigue damage of the electric motor power cables, and extending the service life of the electric motor cables. The electric motor components and the joint connecting rod obviate the need to reserve dedicated cable through holes and a cable placement mechanism, thus allowing enhanced structural reliability; further increasing the degree of integration of a dual joint unit, reducing the axial size of the joint unit, and enhancing structural visual appeal.