Abstract: To develop an "equivalent thickness measurement technique" for non-destructive measurement of ultra-thin carbon nanotube film uranium target thickness, which can address the limitations of traditional measurement methods. The magnetron sputtering was used to prepare uranium targets on carbon nanotube films and stainless steel substrates. The surface emissivity of the uranium target was measured and converted into mass thickness using 2πα and 2πβ multi wire proportional counters, and compared and verified using a liquid scintillation counter. The experimental results show that the maximum deviation between the uranium target thickness measured by this method and the liquid scintillation counter is only −4.8%, which verifies the reliability of this technology; The measurement of samples at different positions also confirmed the uniformity of uranium distribution during the sputtering process. This study successfully established a new non-destructive measurement method that can accurately measure the thickness of ultra-thin uranium targets, providing an effective technical means for uranium target preparation and quality control in related fields.