Objective   To observe the impact of preoperative anterior chamber depth (ACD) on anterior chamber angle morphology after phakic posterior chamber implantable collamer lens (PPC-ICL) implantation. Methods One hundred and thirty-two eyes of 80 consecutive patients with myopia undergoing PPC-ICL implantation were enrolled in this retrospective study. The patients were divided into three groups according to preoperative anterior chamber depth: group A: ACD＜3.0 mm; group B: 3.0≤ACD＜3.5 mm; group C: ACD≥3.5 mm. Before surgery and 3 months after surgery, anterior segment optical coherence tomography (AS-OCT) was used to measure anterior segment morphology. The indexes observed included ACD, angle opening distance (AOD500), trabecular-iris space area (TISA500) and scleral spur angle (SSA) in the 0° and 180° positions. Analysis of variance, correlation analysis and a paired t-test were used for statistical analysis. Results For all the patients, the measured values of preoperative AOD500 (0°, 180°) (r=0.51, 0.47), TISA500 (0°, 180°) (r=0.55, 0.52) and SSA (0°, 180°) (r=0.46, 0.58) were positively correlated with ACD (P＜0.01). Three months after surgery, the average ACD, AOD500, TISA500 and SSA values of the three groups had significantly decreased compared to preoperative values (P＜0.05). The measurements of AOD500 (F=7.00, 5.08), TISA500 (F=6.42, 3.06) and SSA (F=7.20, 4.73) in the 0° and 180° positions in group A were significantly lower than those in groups B and C (P＜0.05), and there was no significant difference between group B and group C. The postoperative AOD500, TISA500 and SSA in the three groups declined in the same proportion, and there were no statistically significant differences. The PPC-ICL vaults in groups A and B were lower than those in group C (F=5.37, P＜0.05). Three months after surgery, the changes (percentage) in AOD500 (r=0.54, 0.50), TISA500 (r=0.49, 0.48) and SSA (r=0.60, 0.61) were positively correlated with ICL vault (P＜0.01). No anterior chamber angle closure was found during the follow-up period, and there was no significant decrease in intraocular pressure in the three groups after surgery. Conclusion The morphology of the anterior chamber changes significantly after PPC-ICL implantation. Patients with a shallow anterior chamber will show a shallower anterior chamber depth and narrower anterior chamber angle after surgery. The change in anterior chamber morphology will be more obvious in patients with a higher vault.