Objective. To investigate the effects of different nonsteroidal anti-inflammatory drugs combined with platelet-rich plasma on inflammatory factor levels in patients with osteoarthritis. Methods. The clinic data of 120 patients with osteoarthritis who were treated in our hospital (June 2019-June 2021) were retrospectively reviewed. All the patients were given platelet-rich plasma. According to the different nonsteroidal anti-inflammatory drugs the patients received, they were equalized into diclofenac sodium group, celecoxib group, and iguratimod group, with 40 cases in each group. After treatment, the patients’ clinical efficacy was compared and analyzed. Results. After treatment, the pain degrees of the patients in the three groups were gradually reduced. After 4 weeks and 8 weeks of treatment, the statistical differences in the scores of Visual Analogue Scale (VAS) were found among the three groups. Specifically, compared with the other two groups, the iguratimod group had remarkably lower VAS scores (
P
<
0.05
) and the celecoxib group had signally lower VAS scores compared with the diclofenac sodium group (
P
<
0.05
). After treatment, the inflammatory factor levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and high-sensitivity C-reactive protein (hs-CRP) in the diclofenac sodium group were observably higher compared with the celecoxib group (
P
<
0.05
), and the inflammatory factor levels in the celecoxib group were remarkably higher compared with the iguratimod group (
P
<
0.05
). Before treatment, no notable difference in the Lysholm scores was found among the three groups, and the patients’ knee joint function was gradually improved after treatment. To be specific, after 4 and 8 weeks of treatment, the iguratimod group had observably higher Lysholm scores compared with the other two groups (
P
<
0.05
), and the celecoxib group had signally higher Lysholm scores compared with the diclofenac sodium group (
P
<
0.05
). The iguratimod group got markedly lower Western Ontario and McMaster Universities (WOMAC) score compared with the celecoxib group (
P
<
0.05
); Compared with the diclofenac sodium group, the celecoxib group got remarkably lower WOMAC score (
P
<
0.05
). During treatment, few patients suffered from mild gastrointestinal discomfort and hepatic dysfunction in the three groups, and no other severe adverse reactions were found. No statistical difference in the total incidence of adverse reactions among the three groups was observed (
P
>
0.05
). Conclusion. The combination of nonsteroidal anti-inflammatory drugs with platelet-rich plasma can further reduce the inflammatory reactions of the patients with osteoarthritis and improve their knee joint function. Significantly, the iguratimod, with high safety, has observably better effects on inhibiting inflammatory factors and improving knee joint function compared with diclofenac sodium and celecoxib.