Flowshop scheduling problem is a kind of typical scheduling problem, and has wide application background. While common in the flowshop environment, the objective of the flowshop with multiple processors dynamic scheduling problem is minimize the total cost of earliness/tardiness and deviation punishment. In this paper, a mathematical model of the problem is presented and a hybrid genetic-particle swarm optimization algorithm is constructed. The simulation results show that this is a better solving method for complex flowshop multiple processors dynamic scheduling problem.