Abstract: A self-shielding accelerator is provided, which includes an accelerator assembly, a high-frequency electrode plate, a rectification and voltage multiplication assembly, a solenoid-type transformer assembly, a cooling system assembly and a shielding steel cylinder. The self-shielding accelerator further includes a steel cylinder base connected to the shielding steel cylinder. The accelerator assembly is horizontally fixed to the steel cylinder base. The rectification and voltage multiplication assembly is fixed to the steel cylinder base by a support plate. The high-frequency electrode plate and the solenoid-type transformer assembly are connected to the steel cylinder base through multiple horizontally arranged support columns. The cooling system assembly is fixed to the shielding steel cylinder. The self-shielding accelerator adopts a fully horizontal self-shielding structure, and can be seamlessly joined to the filling production line, which makes online radiation processing possible.