In this paper, a practical and systematic tuning procedure for fractional order controller using particle swarm algorithm (PSO) based on digital twin (DT) system of industrial robot has been developed. The procedure includes a virtual realization of control system based on digital twin concept. Then a particle swarm algorithm is introduced to optimize the five parameters of the cascade fractional order PI-PIλ controller. The optimization procedure using particle swarm algorithm based on digital twin concept is also presented. Finally, the virtual industrial robot model in digital twin is simulated to verify the applicability of the optimization method. The effectiveness of using the cascaded fractional order PI-PIλ controller compared to the cascaded integer order PI-PI controller is illustrated by the simulation results, where the cascaded fractional order PI-PIλ controller responses faster with smaller tracking error over the integer order one.