This study evaluated the effects of sodium-glucose co-transporter 2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) on glycemic control, islet cell function, and insulin resistance in type 2 diabetes mellitus (T2DM) patients with T1-stage renal cell carcinoma (RCC). A retrospective cohort of 175 patients was divided into a control group receiving SGLT2i monotherapy (n = 84) and an observation group receiving combination therapy with SGLT2i and GLP-1RA (n = 91). Propensity score matching (PSM) was employed to balance baseline characteristics, resulting in 35 patients per group. After treatment, the observation group showed significant improvements in fasting plasma glucose (FPG), 2-hour postprandial glucose (2hPG), and glycated hemoglobin (HbA1c) compared to the control group (P < 0.001). Islet cell function markers, including fasting insulin and HOMA-IR, also improved significantly (P < 0.001). Renal function markers, such as serum creatinine, blood urea nitrogen, and urinary albumin excretion rate, were better in the observation group (P < 0.05). Multivariate analysis identified older age (OR = 7.434, P = 0.025), higher BMI (OR = 6.812, P = 0.003), and high-fat diet (OR = 0.044, P = 0.005) as independent risk factors for insulin resistance. The combined use of SGLT2i and GLP-1RA demonstrated superior efficacy in improving glycemic variability, insulin sensitivity, and renal function, highlighting its potential as an effective strategy for managing patients with T2DM and RCC.