Iterative greedy (IG) algorithm is a meta-heuristic algorithm with strong local search ability, but due to the excessive search range of traditional iterative greedy algorithm and limited search efficiency, in order to further improve the search ability of traditional iterative greedy algorithm, considering the threshold acceptance algorithm has The characteristics of narrowing the search range, an improved iterative greedy algorithm is proposed to solve the problem of order acceptance and scheduling for prefabricated production in flow shop. The improved algorithm is to add a reconstruction strategy based on constructing heuristic rules after destroying the original scheduling sequence, and combined with the adaptive acceptance criterion of the threshold acceptance algorithm to jump out of the local optimum. A large number of simulation experiments show that the improved iterative greedy algorithm has better solution quality and robustness compared with the traditional iterative greedy algorithm, tabu search (TS) algorithm and genetic algorithm (GA).