Objective To investigate the effectiveness of digital three-dimensional (3D) assisted unilateral biportal endoscopy (UBE) in the treatment of highly isolated lumbar disc herniation (LDH) with translaminar approach. Methods The clinical data of 59 patients who met the selection criteria and underwent UBE treatment due to highly isolated LDH between January 2022 and December 2023 were retrospectively analyzed. Among them, 25 cases were treated with digital 3D assisted translaminar approach (observation group) and 34 cases were treated with interlaminar approach (control group). There was no significant difference in gender, age, disease duration, surgical segment, and preoperative visual analogue scale (VAS) score and Oswestry disability index (ODI) between the two groups (P>0.05). The operation time, intraoperative blood loss, and lateral articular surface preservation rate were recorded and compared between the two groups. VAS score and ODI were used to evaluate the improvements of pain and function before operation and at 3 and 6 months after operation. The modified MacNab criteria was used to evaluate the effectiveness at last follow-up. Results One patient in the control group had dural tear, and the other patients had no nerve injury, infection, dural tear, or other related complications. There was no significant difference in operation time and intraoperative blood loss between the two groups (P>0.05). Patients in both groups were followed up 6-13 months, with an average of 8.3 months. The lateral articular surface preservation rate in the observation group was significantly higher than that in the control group (P<0.05). Three patients in the observation group and 2 patients in the control group had calf muscle venous thrombosis, which was cured after anticoagulant treatment with rivaroxaban and delayed exercise time. There was no recurrence or second operation during the follow-up period. The VAS score and ODI of the two groups at 3 and 6 months after operation significantly improved when compared with those before operation (P<0.05). There was no significant difference between the two groups at each time point after operation (P>0.05). At last follow-up, the effectiveness was evaluated according to the modified MacNab criteria, and there was no significant difference in the evaluation grade and excellent and good rate between the two groups (P>0.05). Conclution UBE via translaminar approach is safe and effective for the treatment of highly isolated LDH, which is beneficial to protect the facet joint, maintain spinal stability, and reduce soft tissue injury. With the assistance of digital 3D technique, preoperative planning can be performed accurately.