Abstract: Multi-stage production planning plays an important role in improving the production rate and energy saving in modern manufacturing industry. Based on the analysis of production flow and planning of an electric resistance welding (ERW) manufacturing enterprise, this paper proposes an advanced/delayed punishment mathematical model of multistage production planning. A local optimal solution for it is obtained by the real number-coding genetic algorithm. Simulation results indicate that the model and algorithm are feasible and efficacious. The presented solution has well applied to practical ERW production planning.