To evaluate the long-term subjective and objective visual quality after implantation of a diffractive trifocal intraocular lens (IOL) in high myopic eyes. A total of 53 eyes from 38 patients with high myopia who underwent phacoemulsification and trifocal IOL implantation were investigated. The visual acuity, contrast sensitivity, diopter, defocus curve, and objective visual quality at 1 month, 3 months, 1 year, and 2 years after surgery, as well as the satisfaction questionnaire and VF-14 scale, were statistically analyzed. The average age was 53.14 ± 4.70 years. The average preoperative spherical equivalent was -10.77 ± 3.98 D. Two years after surgery, 94.3% of the patients achieved an uncorrected distance visual acuity of 0.1 (LogMAR), and 84.9% and 94.3% of the patients had SE within ±0.50 D and ±1.0 D, respectively. The defocus curve was smooth and at a high value within the range of 0 D to -2.50 D. In CS or objective visual quality, there was no significant difference at 3 months, 1 year, and 2 years after operation (all P > 0.05). The rate of spectacle independence was 100%. The proportion of patients with moderate or severe glare and halo was 10.5% and 13.2%, respectively. Furthermore, 23.7%, 26.3%, and 18.4% of the patients had difficulties in reading small font, doing delicate tasks, and driving or riding at night, respectively. The diffractive trifocal IOL implantation provided good distance, intermediate, and near uncorrected visual acuity for patients with cataracts and high myopia. It was safe, effective, predictable, and stable. It provided long-term good visual quality after surgery, with high spectacle independence and high patient satisfaction.