Despite the activation of T lymphocytes by antigen-presenting cells is responsible for eliciting antigen-specific immune responses, their crosstalking suffers from temporospatial limitations and endogenous influencing factors, which restrict the generation of a strong antitumor immunity. Here, we describe the manipulation of cross-priming of T cells using biomimetic nanoparticles (BNs) enabled by cascade cell membrane coating. BNs are resulted from coating nanoparticulate substrates with cell membranes extracted from dendritic cells (DCs) that are pre-pulsed with cancer cell membrane-coated nanoparticles. With a DC membrane that presents an array of cancer cell membrane antigen epitopes, BNs inherit intrinsic membrane function of DCs.Strikingly, BNs can directly cross-prime T cells and provoke robust yet antigen-specific antitumor responses in multiple mouse models. Combination with clinical antiprogrammed death-1 antibodies demonstrates a practical way of BNs to achieve desirable tumor regression and survival rate. This work spotlights the impact of nanoparticles on direct cross-priming of T cells and supports a unique yet modulate platform for boosting an effective adaptive immunity for immunotherapy. inoculation with Hepa 1-6 on day 0, the mice were treated with intraperitoneal administration of 100 μg αPD-1 on day 8, 9, 11, 13 and 15 along with daily tail vein injection of HDCNs through day 8 to 14. Equivalent free αPD-1 was used as a control. Mice were sacrificed for sampling once tumor volume in the control group exceeded 2000 mm 3 . Percentages of (a) CD3 + T cells as effector T cells, (b) Ki67 + , (c) IFN-γ + , mean fluorescence intensities of DC indicator (d) CD8 + /Foxp3 + CD25 + CD4 + ratio, (e) CD80 and (f) CD86, and (g) MHC-II in the spleen. Levels of (h) CD3 + CD4 + , (i) IFN-γ and (j) TNF-α in the serum. (k) Average and (l) individual tumor growth curves of the treated mice. Error bars represent the standard deviation (n = 5). Significance was assessed using One-way ANOVA with Dunnett's post-hoc test. ****p < 0.0001, ***p < 0.001 and **p < 0.01.