Abstract: Biomass waste fermentation system is a large time delay system.In view of problems of high fluctuation，high shock and super adjustment of heat control in biomass waste fermentation system，PID control method for fermentation heat energy in biomass waste based on improved invasive weed optimization algorithm was proposed.Parameters of PID controller can be adjusted online by using improved invasive weed algorithm.Simulation of the study showed that the method proposed in the study could achieve heat energy control in biomass waste fermentation system quickly，steadily and accurately，provide stable heat environment for biogas production，and achieve stable supply of biogas.