Objective To compare the effectiveness of I.D.E.A.L technique and transtibial (TT) technique in anterior cruciate ligament (ACL) reconstruction. Methods A clinical data of 60 patients with ACL injury, who were admitted and met the selection criteria between January 2020 and September 2022, was retrospectively analyzed. All patients underwent arthroscopic ACL reconstruction with autologous tendon. During operation, the femoral tunnel was prepared by using I.D.E.A.L technique in 30 cases (I.D.E.A.L group) and using TT technique in 30 cases (TT group). There was no significant difference in baseline data such as age, gender, body mass index, cause of injury, injured side, interval from injury to operation, constituent ratio of combined cartilage and meniscus injury, and preoperative Lysholm score, International Knee Documentation Committee (IKDC) score, visual analogue scale (VAS) score, anterior tibial translation difference, and Blumensaat angle between the two groups (P>0.05). The length of hospital stay and the occurrence of early and late complications were recorded. During follow-up, the Lysholm score, IKDC score, and VAS score were used to evaluate knee joint function and pain degree, and the anterior tibial translation difference was measured. MRI reexamination was performed to observe the healing of the graft, and the signal to noise quotient (SNQ) values of the femoral end, middle section, and tibial end of the graft, as well as the Blumensaat angle of the knee joint were measured. The differences in tibial anterior translation difference and Blumensaat angle before and after operation (change values) were calculated and compared between the two groups. Results The incisions in both groups healed by first intention after operation, and there was no significant difference in the length of hospital stay between the two groups (P>0.05). All patients were followed up 12-18 months, with an average of 14.9 months. The Lysholm score and IKDC score of the knee joint in both groups after operation increased when compared with those before operation, and the VAS score decreased. Compared to preoperative scores, except for the VAS score of the TT group at 1 week after operation (P>0.05), there were significant differences in all scores at different time points postoperatively in the two groups (P<0.05). The above scores in both groups showed a further improvement trend with the prolongation of time after operation. There were significant differences in Lysholm score and VAS score among 1 week, 1 month, 3 months, 6 months, and 12 months after operation in the two groups (P<0.05). The IKDC score of both groups at 1 month after operation was significantly different from that at 1 week after operation (P<0.05). At 1 week after operation, the Lysholm score and IKDC score in the I.D.E.A.L group were significantly higher than those in the TT group (P<0.05), and the VAS score was significantly lower (P<0.05); there was no significant difference between the two groups at 1, 3, 6, and 12 months after operation (P>0.05). At 12 months after operation, the anterior tibial translation differences in both groups were significantly lower than those before operation (P<0.05); and the change value in the I.D.E.A.L group was significantly higher than that in the TT group (P<0.05). The incidences of early and late complications in the I.D.E.A.L group were significantly lower than those in the TT group (P<0.05). At 12 months after operation, MRI examination showed that the grafts of the knee joint in both groups survived well, and the Blumensaat angles of both groups were significantly smaller than those before operation (P<0.05). The change value of the Blumensaat angle in the I.D.E.A.L group was significantly higher than that in the TT group (P<0.05). The SNQ values of the femoral end, middle section, and tibial end of the graft in the I.D.E.A.L group were significantly higher than those in the TT group (P<0.05). Conclusion The early effectiveness of ACL reconstruction by using the I.D.E.A.L technique is better, the knee joint is more stable, and the incidence of postoperative complication is lower. However, the maturity of the graft after reconstruction using the TT technique is higher.