The present invention discloses a dynamic feed combination selection system and a selection method based on an ant colony algorithm, belonging to the technical field of pig farm breeding. The invention provides a feed combination optimization method based on an ant colony algorithm. The method comprises a step of randomly selecting n kinds of service providers in all service providers to be selected, forming a dynamic combination model according to a constraint condition, and forming a multi-target decision-making problem with satisfaction of constraint, a step of carrying out solution for a model comprehensive application ant colony algorithm, a step of carrying out updating according to an optimization mode selected by the algorithm until the information elements of the elements in an obtained combination are converged to the optimal solution, and a step of outputting the optimal solution to be the final selection of the service providers. According to the method, the practical application of the ant colony algorithm in the selection process of the service provider of pig farm breeding is realized, thus a basis is provided for the selection of the service provider of the pig farm breeding, a maximum absorption rate is obtained with minimal cost, the cost is reduced, and the income is raised.