The invention discloses application of a model constructed based on a PCD related gene combination in preparation of a product for predicting prognosis of colonic adenocarcinoma. 14 PCD key genes differentially expressed in colorectal cancer, including (SPTBN2, DNAJC2, DRD4, SH3GL3, FOXS1, GSTM1, ISSYNA1, NOL3, GPR27, PPARGC1A, RAB36, SEZ6L2, SERPINE1 and TNNT1), are adopted as detection targets to construct a prognosis model PCDSig, the model has good clinical prognosis prediction ability for one year, two years and three years, the model can better distinguish high-risk people from low-risk people, and high-risk and low-risk patients have the characteristics of immune infiltration, immune deficiency, immune deficiency, immune deficiency, immune deficiency, immune deficiency, immune deficiency, immune deficiency, immune deficiency, immune deficiency, immune deficiency and the like. The response of immunotherapy is different from the aspects of drug target gene expression and chemotherapy drug sensitivity, target benefit people can be screened through the model, clinical precise and personalized treatment is effectively guided, and excessive treatment and patient condition delay are avoided. On the basis of the model, a column diagram for predicting the survival probabilities of the patient in one year, three years and five years is developed, so that the model is visualized, and conditions are provided for clinicians to judge the prognosis of the COAD patient.