Optoelectronic MOS solid-state relays integrate optoelectronic isolation technology with MOSFET processes, achieving reduced device dimensions and expanding application domains. Currently, there is limited research on this type of device both domestically and internationally, Particularly when exposed to complex radiation environments, the reliability of the device requires evaluation. This paper investigates the total dose resistance characteristics of the input-side LED and output-side MOS device in a specific opto-MOS solid-state relay model through gamma-ray total dose irradiation experiments. Experimental results indicate: Within the 0–100k rad (Si) dose range, the device's LED terminal exhibits excellent radiation resistance in forward characteristics, while reverse characteristics demonstrate sensitivity to ionizing radiation. Within the 0–300k rad (Si) dose range, the device's turn-on voltage remains stable. However, the turnon resistance of the MOS terminal and the turn-off leakage current are significantly affected by radiation, showing a marked upward trend with increasing cumulative dose.