The kit is a blocking CLIA detection tool designed to mimic the virus neutralizing process after the vaccination in the natural immune response. The kit contains two key components, the ALP-labeled SARS-CoV-2 S protein receptor binding domain(RBD-ALP) and magnetic bead-labeled human ACE2 receptor protein(M-ACE2). The binding between SARS-CoV-2 RBD and human ACE2 in the virus invasion could be blocked by neutralizing antibodies against the SARS-CoV-2 RBD. When samples are mixed with the RBD-ALP, the neutralizing antibodies bind to the RBD-ALPs and will be removed after washing. Meanwhile, both the unbound RBD-ALPs and the RBD-ALPs bound to the non-neutralizing antibodies will be captured by the M-ACE2 to form the complex. After washing, the luminescent substrate is added and catalyzed by the enzyme in the complex to form unstable exited state intermediates. When the exited intermediates return to the ground state, photons are emitted. The number of photons produced is negatively correlated with the content of neutralizing antibodies in the sample.