Abstract: Objective To analyze the curative effect of breast cancer combined with three dimensional conformal radiotherapy on breast conserving surgery for early breast cancer. Methods According to the number of admission cases, 170 patients with early breast cancer who were admitted to hospital from January, 2013 to December, 2015 were divided into two groups randomly. The control group and the observation group (85 cases each) were treated with breast conserving surgery. After operation, two-field tangent whole breast irradiation was given.The control group was treated with conventional tumor bed electron line, and the observation group was treated with tumor bed volume plus three dimensional conformal radiotherapy. The patients were followed up for 36 months. The target homogeneity index (HI), target conformity index (CI), skin cosmetic effect and adverse reaction were observed and compared between the two groups. The local recurrence rate and distant metastasis rate were also compared. Results The target homogeneity index (HI) and target conformity index (CI) of the observation group were better than those of the control group (t=8.746, P<0.05; t=8.005, P<0.05). No grade 3-4 skin adverse reactions occurred in the observation group,and the incidence of acute and late skin adverse reactions was lower than that in the control group (χ²=7.784, P<0.05; χ²=5.749, P<0.05). The excellent and good rate of cosmetic effect in the observation group was higher than that in the control group,with statistical significance (Z=4.181, P<0.05). There was no significant difference in the local recurrence rate and distant metastasis rate between the two groups (χ²=2.024, P>0.05; χ²=0.206, P>0.05;). Conclusion Tumor bed dosage combined with three-dimensional conformal radiotherapy has a uniform measurement, a good target conformity, a low incidence of skin adverse reactions,a good cosmetic effect,more in line with the aesthetic needs of women with breast cancer.