The invention discloses a fresh cordyceps militaris combined drug for anti-tumor chemotherapy. The fresh cordyceps militaris combined drug contains a fresh cordyceps militaris extract and cis-platinum, wherein the fresh cordyceps militaris extract is prepared from the raw material fresh cordyceps militaris by taking water as an extraction solvent through flash extraction and ultrafiltration. More particularly, the fresh cordyceps militaris extract has toxicity reducing and efficacy enhancing effects to the adjuvant therapy of the tumor chemotherapy and is capable of enhancing the inhibition effect of chemotherapy medicines to the growth of lung carcinoma cells and protecting injury of liver and kidney tissues caused by the chemotherapy medicines. The fresh cordyceps militaris extract provided by the invention has remarkable toxicity reducing and efficacy enhancing effects to the adjuvant therapy of the tumor chemotherapy, the protection effect of the fresh cordyceps militaris extract to the injury of the liver and kidney tissues caused by the chemotherapy medicines is found for the first time, and scientific basis and important information are provided for the further research of novel use and drug action mechanisms.