Substrate stiffness is one of the important mechanical parameters of extracellular matrix. Different substrate stiffness will affect the proliferation, movement and phenotype of tumor cells. It is found that the change of substrate stiffness is also related to the chemotherapy and radiotherapy sensitivity of tumor cells. Substrate stiffness can cause changes in the characteristics of tumor stem cells, which are related to the activation or inactivation of some signaling pathways, mainly involving ABCG2 protein and Akt/mTOR/Sox2 signaling pathway. Further study on the role of substrate stiffness in radiotherapy, chemotherapy and targeted therapy of malignant tumor is expected to provide basis for the clinical treatment of malignant tumor.