Poor immunogenicity seriously hampers the broader implementation of antitumor immunotherapy. Enhanced immunogenicity capable of achieving greater antitumor immunity is urgently required. Here, a novel polymer that contains hydrophobic ferrocene (Fc) units and thioketal bonds in the main chain, which further delivered a prodrug of oxaliplatin and artesunate, i.e., Artoxplatin, to cancer cells is described. This polymer with Fc units in the nanoparticle can work as a polyigniter to spark the peroxide bonds in Artoxplatin and generate abundant reactive oxygen species (ROS) to kill cancers as nanobombig for cancer therapy. Moreover, ROS can trigger the breakdown of thioketal bonds in the polymer, resulting in the biodegradation of the polymer. Importantly, nanobombig can facilitate the maturation of dendritic cells and promote the activation of antitumor immunity, through the enhanced immunogenic cell death effect by ROS generated in situ. Furthermore, metabolomics analysis reveals a decrease in glutamine in nanobombig‐treated cancer cells, resulting in the upregulation of programmed death ligand 1 (PD‐L1). Consequently, it is further demonstrated enhanced tumor inhibitory effects when using nanobombig combined with anti‐PD‐L1 therapy. Overall, the nanosystem offers a rational design of an efficient chemo‐immunotherapy regimen to promote antitumor immunity by improving tumor immunogenicity, addressing the key challenges cancer immunotherapy faced. A strategy for promoting chemo‐immunotherapy by simultaneously delivering oxaliplatin and artesunate into the tumor using a nanoparticle containing ferrocene units, named nanobombig, which facilitates the maturation of dendritic cells and promotes the activation of antitumor immune response, through the enhanced immunogenic cell death effect by reactive oxygen species generated in situ.