Objective To study mathematical model and to perform computer simulation for an important subsystem in the bioregenerative life support system(BLSS),i.e.,light-algae bioreactor(LABR)forcontinuously cultivating green microalgae andsignificantly maintaining life support function of BLSS.MethodsBased on the theories of system dynamics and stoichiometry,the mathematical model and simulation model of LABR were respectively established with experimental data,and then computer experiments were conducted to simulate dynamic responses of LABR under different parameters as well as their combinations.Results It was shown that the kinetic model of LABR was valid for its real-life counterpart by a series of verification tests.It could reliably and beneficially provede technical and methodologcal helps for further investigations of LABR,such as theoretical analysis,design,control and optimization,and so on.Conclusion With computer experiments based on mathematical model and simulation model,it decreases much more in time and money consumption for investigations than with real experiment.This method can also be extended to use in other subsystems studies of BLSS.