Researchers conducted a study that looked backward. For a study, they sought to determine the parameters that affect operation length in Lenke 1 and 2 AIS patients undergoing posterior spinal fusion (PSF) surgery with a dual attending surgeon strategy. A total of 260 AIS patients with Lenke 1 and 2 curves who had PSF were evaluated retrospectively. Age, sex, height, weight, BMI, Risser grade, Lenke subtypes, number of fusion levels, number of screws, screw density, wound length, upper and lower instrumented vertebrae level, preoperative Cobb angle, and flexibility of the significant curve were assessed using univariate and multivariate linear regression analyses. When the P-value was less than 0.05, independent factors were identified. The average operation took somewhere between 122.2 and 28.6 minutes to complete. Lenke 2 subtypes (β=8.86, P=0.008), number of screws (β=7.01, P<0.001), wound length (β=1.14, P=0.009), and flexibility of the primary curve (β=−0.25, P=0.005) were all significant independent factors determining operation duration in PSF among Lenke 1 and 2 AIS patients. R2=0.525 was the overall model fit. The formula: (8.86×Lenke subtypes)+(7.01×number of screws)+(1.14×wound length)−(0.25×flexibility)−0.54, where Lenke 2=1 and Lenke 1=0, can be used to determine operation duration. Lenke 2 curves, number of screws, wound length, and curve flexibility influenced operation duration in PSF among Lenke 1 and 2 AIS patients. Knowing the characteristics allowed spinal deformity surgeons to plan and predicted the length of the procedure before AIS surgery.