Biomacromolecule therapeutic systems are intrinsically susceptible to degradation and denaturation. Nanoformulations are promising delivery vehicles for therapeutic biomacromolecules (antibodies, genes and so on). However, their applications in these areas still face many challenges including in vivo stability, premature leakage and accurate tumor recognition. In this study, a generally applicable new strategy for tumor-targeted delivery of biomacromolecules was developed through the hierarchical integration of degradable large-pore dendritic mesoporous silica nanoparticles (dMSNs) and cyclodextrin-modified polyamidoamine (PAMAM-CD) dendrimers. The orifice rim of the dMSNs was modified with ROS-responsive nitrophenyl-benzyl-carbonate (NBC) groups while disulfide-bonded azido ligands were subsequently grafted onto the inner channel walls via heterogeneous functionalization. The PAMAM-CD was then interred into the dendritic pores via click reactions and supramolecularly loaded with archetypal hydrophobic small-molecule anticancer model drug (SN-38) and therapeutic model gene (Bcl-2 siRNA), after which dMSNs were eventually coated with a 4T1 cancer cell membrane (CCM). Experimental evidence demonstrated that the synthesized nanocarriers could efficiently deliver therapeutic cargos to target cancer cells and release them in the tumor cytosol in a cascade-responsive manner. This biomimetic nanoplatform presents a novel strategy to efficiently deliver biomolecular therapeutics in a tumor-targeted manner.