To explore the most effective adjuvant chemotherapy regimen for malignant peritoneal mesothelioma (MPM) through patient derived tumor-like cell clusters (PTC) drug sensitivity test. PTC were cultured in vitro with intraoperative specimens, and drug sensitivity test was performed to calculate the most effective chemotherapy regimen for MPM. The patients were divided into conventional and individualized chemotherapy group according to whether they received PTC drug testing. Univariate and multivariate analyses were conducted to identify independent prognostic factors. Among 186 MPM patients included, 63 underwent PTC culture and drug sensitivity test. The results showed that the most effective chemotherapy regimen was oxaliplatin + gemcitabine. After propensity score matching, a total of 64 patients were enrolled in the following study, including 32 patients receiving individualized chemotherapy guided by PTC drug results as group 1 and 32 patients receiving conventional chemotherapy as group 2. Survival analysis showed that the median OS of group 1 was not reached, significantly longer than that of group 2 (23.5 months) (p < 0.05). Compared with conventional chemotherapy, individualized chemotherapy guided by PTC drug sensitivity tests can prolong patient survival, and oxaliplatin + gemcitabine + apatinib could be the optimal adjuvant treatment regimen for MPM.