Objective To investigate the effect of modified Miccoli surgery on patients with unilateral thyroid cancer(TC)and its impact on the body's traumatic stress response.Methods The data of 200 patients with unilateral TC in Xinmi City Hospital of Traditional Chinese Medicine from March 2021 to March 2023 were retrospectively collected and divided into two groups according to different surgical protocols.A hundred patients treated with modified Miccoli surgery were classified as group A and 100 patients treated with open radical surgery(OT)were classified as group B.The perioperative indicators,incidence of recurrent laryngeal nerve injury,aesthetic effect,as well as tumor indicators[cytokeratin 19 fragment antigen(Cyfra21.1),galectin-3(Gal-3),soluble interleukin-2 receptor(sIL-2R)]and trauma stress response indicators[norepinephrine(NE),epinephrine(E),and cortisol(Cor)]before and after surgery were compared between the two groups.Results The incision length of group A was(2.05±0.13)cm,which was shorter than that of group B[(7.11±0.49)cm].The duration of hospitalization and operation of group A were(3.12±0.44)d and(53.48±7.52)min,respectively,which were shorter than those of group B[(5.22±0.81)d and(76.81±11.39)min].The intraoperative blood loss and drainage volume were(19.24±2.66)mL and(21.47±3.41)mL,respectively,which were lower than those in group B[(45.08±5.75)mL and(64.82±7.24)mL],and the difference was statistically significant(P<0.05).The total incidence of recurrent laryngeal nerve injury in group A was 2.00%(2/100),lower than that in group B[12.00%(12/100)],and the difference was statistically significant(P<0.05).The total satisfaction of group A was 97.00%(97/100),higher than that of group B[73.00%(73/100)],and the difference was statistically significant(P<0.05).Serum Cyfra21.1 and Gal-3 levels in group A were(1.78±0.26)ng/mL and(6.14±1.64)ng/mL,respectively,higher than those in group B[(1.55±0.21)ng/mL and(5.39±1.28)ng/mL].Serum sIL-2R level was(375.36±20.12)μg/mL,lower than that of group B[(427.13±23.18)μg/mL],and the difference was statistically significant(P<0.05).The serum levels of NE,E and Cor in group A were(0.73±0.17)mmol/L,(0.49±0.10)mmol/L and(185.46±22.95)μg/L,respectively.They were lower than(0.96±0.19)mmol/L,(0.81±0.22)mmol/L and(272.53±32.41)μg/L in group B,and the differences were statistically significant(P<0.05).Conclusions Compared to OT treatment for unilateral TC patients,the modified Miccoli surgery is more helpful in improving aesthetic effects,reducing damage to the recurrent laryngeal nerve,optimizing perioperative indicators,inhibiting tumor progression,and producing less traumatic stress response to the body.