Abstract: In this paper，a parameter optimization model is established based on the two-stage nonlinear dynamical system with terminal state constraint of bio-dissimilation of glycerol to 1，3-propanediol（1，3-PD） in microbial batch culture.In the model，the authors consider both the initial concentrations of glycerol and biomass and fermentation time as the parameters to be optimized as well as the maximum productivity of 1，3-PD at terminal time as the cost function.Subsequently，the existence of the optimal parameters is proved.Finally，the authors construct an improved simplex method to solve this problem and the numerical results give the optimal fermentation time，initial biomass and concentration of glycerol in the microbial batch culture.The results can provide a theoretical instruction for the production of 1，3-PD.