An effective migratory bird optimization algorithm was proposed to aim at the optimized problem of productive planning of assemble workshop under the limitation of the number of molds, and the variable batch division strategy with unequal quantity was considered. The lot streaming hybrid assembly flow shop scheduling problem was studied. In the algorithm, a two-stage coding mechanism of batch partitioning and ordering was designed according to the assembly constraints on various products of each production stage. The multiple neighborhood structures were designed according to the coding characteristics, including a neighborhood structure that simultaneously optimized the batch division and ordering. An adaptive adjustment strategy of neighborhood structure was proposed to improve the search performance of domain structure. The competition mechanism was designed to improve the efficiency of algorithm optimization. The simulation results of different scale examples showed that the unequal variable batch strategy was more effective than the equal batch strategy by 5%~6%. The unequal strategy provided a reasonable production plan for the workshop. The effectiveness and robustness of the effective migratory bird optimization algorithm compared with other algorithms were verified.