The invention provides core-shell structured gold cluster-carbon dot nano-particles as well as a preparation method and application thereof. According to the gold cluster-carbon dot nano-particles, carbon dots are taken as a template, a nano gold cluster exists inside the template, the nano gold cluster and the carbon dots are connected by virtue of Au-N coordinate bonds, and the particle size of the gold cluster-carbon dot nano-particles is 3-5nm. The preparation method of the gold cluster-carbon dot nano-particles comprises the following steps: by taking carbon dots synthesized from polyethylene-polyamine and citric acid as a template, adding chloroauric acid, enabling the components to react in the presence of a reducing agent, so as to obtain the gold cluster-carbon dot nano-particles. The gold cluster-carbon dot nano-particles provided by the invention are uniform in particle size and good in dispersity, the nano gold cluster and the carbon dots are connected by virtue of the Au-N coordinate bonds, and the gold cluster is kept stable and is difficult to aggregate. The gold cluster-carbon dot nano-particles provided by the invention can be applied to intracellular oxidative stress amplification for tumor treatment.