The invention discloses a dynamic ant colony fast optimization method for cloud manufacturing service combination. According to the method, a fitness function F is obtained from the four aspects of the comprehensive cost C, the time T, the quality function Q and the satisfaction S on a QoS (Quality of Service) evaluation model of cloud manufacturing service combination according to a user request, searching is conducted by applying an improved ant colony algorithm, and combination services are allocated according to the optimization result. The optimized searching process comprises the two stages that 1, global searching is conducted on ants, and large random perturbation is added; and 2, local searching is conducted on the ants, and small random perturbation is added; and it is guaranteed that the algorithm does not fall into local optimum in the early period and has the high convergence speed in the later period. According to the method, the problems that an original ant colony algorithm is likely to fall into a locally optimal solution, low in convergence speed and likely to generate searching stagnation can be solved, and a good effect is achieved for solving the large-scale cloud manufacturing service combination problem.