Objective: To evaluate the therapeutic efficacy of combining Bisinusitis Oral Liquid with mometasone furoate nasal spray in children with chronic rhinosinusitis (CRS), and its effects on serum inflammatory factors and immune function. Methods: A total of 114 pediatric CRS patients were enrolled and assigned to two groups: a control group (n=57) and an observation group (n=57) according to different treatment options. The control group received mometasone furoate nasal spray monotherapy, while the observation group received the nasal spray combined with Bisinusitis Oral Liquid. Both groups were treated for 2 weeks. The Visual Analogue Scale (VAS) score, Traditional Chinese Medicine (TCM) primary symptom score, physical sign score, nasal mucociliary clearance function [assessed by mucociliary transport rate (MTR) and mucociliary clearance rate (MCR)], serum inflammatory factors [C-reactive protein (CRP), interleukin-6 (IL-6)], and immune function [serum immunoglobulin A (IgA), immunoglobulin G (IgG), nasal secretory immunoglobulin (sIgA)] were compared between the two groups. Treatment efficacy was also assessed. Results: The total effective rate was higher in the observation group compared to the control group (P<0.05). After treatment, the observation group demonstrated lower VAS scores, TCM primary symptom scores, physical sign scores, and serum levels of CRP and IL-6 than those of the control group (P<0.05). Conversely, MTR, MCR, serum levels of IgA, IgG and nasal cavity sIgA level were higher in the observation group (P<0.05). Conclusion: The combination of Bisinusitis Oral Liquid with mometasone furoate nasal spray shows superior efficacy in treating pediatric CRS compared to monotherapy. This combined regimen effectively alleviates clinical symptoms, improves nasal mucociliary clearance function, reduces systemic inflammation, and modulates immune responses.