Objective To investigate the effects of ergometer cycling training based on the internet of things and quadriceps strengthening based on internet mobile phones on joint stiffness, function and walking ability in patients with knee osteoarthritis (KOA) in a community setting. Methods KOA patients attending West China Hospital, Sichuan University were selected between April and July 2022. The patients were randomly divided into ergometer cycling group, quadriceps strengthening group and control group (treated with traditional therapy) using a random number table method. The patient underwent a 12 week intervention. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) scale, Timed Up and Go Test (TUG) were used to evaluate the degree of joint stiffness, joint function and walking ability of patients. Data was collected and evaluated before intervention and at 4, 8, and 12 weeks after the initial intervention.Results A total of 72 patients were included, with 24 cases in each group. There were interactive effects between group and time in WOMAC joint stiffness score, joint functional score and TUG test time (P<0.05). At 8 and 12 weeks after intervention, the joint stiffness scores of the ergometer cycling group and the quadriceps strengthening group were better than those of the control group. At 4, 8 and 12 weeks after intervention, the joint function scores of the ergometer cycling group and the quadriceps strengthening group were better than those of the control group (P<0.05). At 8, 12 weeks after intervention, the TUG test scores of the ergometer cycling group were better than those of the control group and the quadriceps strengthening group (P<0.05). Conclusions In a community setting, both 12-week Internet of thing-based ergometer cycling and internet video-based quadriceps strengthening were effective on improving knee stiffness and function in KOA patients and were superior to traditional methods, the two effects were comparable. Ergometer cycling is superior to quadriceps strengthening and traditional methods in improving walking ability.