We present a routinized and reliable method to obtain source catalogs from the Nuclear Spectroscopic Telescope Array (NuSTAR) extragalactic surveys of the Extended Chandra Deep Field-South (E-CDF-S) and Chandra Deep Field-North (CDF-N). The NuSTAR E-CDF-S survey covers a sky area of <inline-formula><tex-math id="M1">\begin{document}$\sim30'\times30'$\end{document}</tex-math> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="JUSTC-2023-0032_M1.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="JUSTC-2023-0032_M1.png"/> </inline-formula> to a maximum depth of <inline-formula><tex-math id="Z-20230704083543">\begin{document}$\sim230\;{\rm{ks}}$\end{document}</tex-math> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="JUSTC-2023-0032_Z-20230704083543.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="JUSTC-2023-0032_Z-20230704083543.png"/> </inline-formula> corrected for vignetting in the 3–24 keV band, with a total of 58 sources detected in our E-CDF-S catalog; the NuSTAR CDF-N survey covers a sky area of <inline-formula><tex-math id="M3">\begin{document}$\sim7'\times10'$\end{document}</tex-math> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="JUSTC-2023-0032_M3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="JUSTC-2023-0032_M3.png"/> </inline-formula> to a maximum depth of <inline-formula><tex-math id="Z-20230704083612">\begin{document}$\sim440\;{\rm{ks}}$\end{document}</tex-math> <graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="JUSTC-2023-0032_Z-20230704083612.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="JUSTC-2023-0032_Z-20230704083612.png"/> </inline-formula> corrected for vignetting in the 3–24 keV band, with a total of 42 sources detected in our CDF-N catalog that is produced for the first time. We verify the reliability of our two catalogs by crossmatching them with the relevant catalogs from the Chandra X-ray observatory and find that the fluxes of our NuSTAR sources are generally consistent with those of their Chandra counterparts. Our two catalogs are produced following the exact same method and made publicly available, thereby providing a uniform platform that facilitates further studies involving these two fields. Our source-detection method provides a systematic approach for source cataloging in other NuSTAR extragalactic surveys.