To study the effects of different ways of importing the membrane stress and different stress values on diagonal extendable solar sail craft, the finite element simulation analysis is carried out. In detail, the necessity of importing the membrane stress and its reasonable value range are overviewed and three ways of importing the membrane stress are introduced. Based on the finite element software ABAQUS, the model of the 20 m×20 m solar sail craft made by European Space Agency (ESA) and German Aerospace Center (DLR) is established. The structure analysis of the model is performed with static nonlinear method considering the three ways of importing the membrane stress. Furthermore, comparative analysis is made on the membrane stress distribution and the effects of membrane stress on the structural rigidity as well as sail state of solar sail are evaluated. In general, the observations in this paper are significant for further research on space solar sail prototype. The results show that stress concentration occurs on the solar sail corner of membrane surface under different ways of importing the membrane stress, while the fold distribution of the membrane surface is different, frequency increases with the increasing of the importing membrane stress, which is beneficial to overall movement of the solar sail craft.