Objective To investigate the latent categories of symptom cluster characteristics in patients with knee osteoarthritis (KOA) after total knee arthroplasty (TKA), and compare the quality of life between these categories. Methods Patients undergoing TKA for KOA in the joint surgery departments of four tertiary-level A hospitals in Urumqi, Xinjiang between November 2023 and March 2024 were selected for the study using the convenience sampling method. Symptoms of postoperative pain, swelling, anxiety, depression, and sleep disorders were collected from patients for latent class analysis using Mplus 8.3 software, and their influencing factors and differences in quality of life between categories were analyzed using SPSS 26.0 software. Results A total of 380 copies of questionnaire were distributed and 362 valid ones were returned, with a validity rate of 95.3%. Of the 362 patients, 342 (94.5%) had symptom cluster. The 342 patients aged 47-85 years, with a mean age of (65.25±7.03) years; 83 (24.3%) were male and 259 (75.7%) were female. According to the postoperative symptom cluster, the patients could be categorized into 3 latent categories: high-symptomatic group (16.1%), low-symptomatic group (51.8%), and high swelling group (32.2%). Compared to the low-symptomatic group, the current being the first joint surgery was a risk factor for the high-symptomatic group [odds ratio (OR)=2.732, 95% confidence interval (CI) (1.216, 6.139), P=0.015], whereas body mass index between 24.0 and 27.9 kg/m2 was a protective factor for the high-symptomatic group [OR=0.362, 95%CI (0.156, 0.840), P=0.018]; body mass index <24.0 kg/m2 was an independent risk factor for the high swelling group [OR=2.769, 95%CI (1.321, 5.803), P=0.007]. Comparison of the quality of life of patients in the 3 latent categories revealed that the high-symptomatic group had the lowest quality of life scores (P<0.05). Conclusion Post-TKA symptom cluster in patients with KOA can be classified into 3 potential categories, and the quality of life performance is different among different categories, so precise symptom management strategies should be provided according to the symptom characteristics of the patients to improve their quality of life.