The standardized mean difference (SMD) at T 3 and T 4 levels for radiationworkers was -0.19 (-0.37, -0.01) and -0.34 (-0.38, -0.30), lower than that of control group ( Z=2.07, -16.06, P<0.05). The SMD at FT 4 levels for radiationworkers was 0.22 (0.06, 0.39), higher than control group ( Z=2.61, P<0.05). The relative risk of thyroid nodules in radiationworkers was 1.47 (1.19, 1.82), higher than that of control group ( Z=-3.58, P<0.05). The analysis result for subgroup showed that the SMD for T 3, T 4 and TSH levels in the interventional radiologyworkers were -0.29 (-0.51, -0.07), -0.31 (-0.47, -0.15) and -0.43 (-0.73, -0.13) ( Z=-2.55, -3.86, -2.82, P<0.05), respectively, and the SMD for T 4 levels in the nuclear medicineworkers was -0.26 (-0.45, -0.07), which meaned a reduced risk compared to the control group ( Z=-2.70, P<0.05).