Abstract: Based on the performance of conventional nuclear power cable with miniaturized radiation resistant and anti-interference coaxial cable, a new type of nuclear reactor core detector cable was successfully developed by developing insulation materials, designing cable structure, adjusting production process and other methods.Compared with original nuclear reactor core detector cable, the developed cable had an outer diameter of 12.3 mm, accumulated radiation dose of 1.0×10⁶ Gy, and transfer impedance of 28 mΩ·m^-1, which met the requirements of practical usage scenarios. In the process of practical use, the miniature radiation resistant and interference resistant coaxial cable was more widely used, and could be applied to nuclear reaction devices smaller than existing nuclear power plants, such as test reactors, space reactors, nuclear powered underwater vessels, etc.