Abstract: Cyber physical system model of coal preparation plant was established. Dynamic alliance method was applied in task scheduling of the cyber physical system. A task scheduling algorithm for the cyber physical system of coal preparation plant was proposed which was based on an improved discrete particle swarm optimization algorithm. In the improved algorithm, discrete particle swarm optimization algorithm is used for global optimization, and tabu search algorithm is adopted for local search, so as to obtain the globally optimal solution. The simulation results show that the improved algorithm improves convergence rate and precision of task scheduling and average utilization of processor.