Objective To investigate the effect of camrelizumab + apatinib combined with radiotherapy on the expression of TRIM27, SCC-Ag, and CYFRA21-1 in advanced oligometastatic non-small-cell lung cancer (NSCLC). Methods A retrospective analysis of patients with oligometastatic NSCLC who were treated at our hospital from January 1, 2021, to March 31, 2022. Patients who met the inclusion criteria were summarized into an observation group (camrelizumab on the basis of the control group), or a control group (radiotherapy combined with oral apatinib). The disease control rate, immune function, changes in the levels of TRIM27, SCC-Ag, CYFRA21-1, and the occurrence of adverse effects were compared between the two groups. Result There were 86 patients who met the inclusion criteria, with 53 cases in the observation group and 33 cases in the control group. There were significant differences in complete remission (CR, 25/53 vs. 10/33), partial remission (PR, 17/53 vs. 12/33), disease control (DC, 7/53 vs. 4/33), disease progression (DP, 4/53 vs. 7/33), and disease control rate (49/53 vs. 26/33) between the observation group and the control group. There was no significant difference in immune function between the two groups before treatment (p > 0.05). After treatment, the levels of CD3+, CD4+, CD4+/CD8+ t cells, and NK cells in the observation group were higher (p=0.015, 0.035, 0.003, 0.001, respectively), while the level of CD8+ t cells was lower (p 0.05). After treatment, the observation group had lower levels of TRIM27 (p=0.035), SCC-Ag (p=0.045), and CYFRA21-1 (p=0.003). There was no significant difference in the occurrence of adverse events between the two groups (p < 0.05). Conclusion Treatment of camrelizumab + apatinib combined with radiotherapy is effective for advanced oligometastatic NSCLC, with mild adverse effects.