An application of a CDK inhibitor and an oncolytic virus in the preparation of an antitumor drug. A CDK inhibitor can be used in the preparation of an oncolytic virus-based antitumor potentiator. Provided are a pharmaceutical composition comprising the CDK inhibitor and the oncolytic virus, a drug kit comprising the CDK inhibitor and the oncolytic virus, and a use of the CDK inhibitor and the oncolytic virus in the treatment of tumors, particularly the tumors not sensitive to the oncolytic virus.本發明屬於生物醫藥領域,涉及CDK(cyclin-dependent kinase,週期蛋白依賴性激酶)抑制劑和溶瘤病毒在製備抗腫瘤藥物的用途。本發明首次發現CDK抑制劑可以用於製備溶瘤病毒抗腫瘤增效劑。發明同時涉及一種包含CDK抑制劑以及溶瘤病毒的藥物組合物,包含CDK抑制劑及溶瘤病毒的藥品套組,以及CDK抑制劑與溶瘤病毒在治療腫瘤,特別是對所述溶瘤病毒不敏感的腫瘤中的用途。