The disclosure provides an application of an anthocyanin extract in preparing a pharmaceutical composition for preventing and treating cardiac toxicity induced by Anthracyclines and the pharmaceutical composition, wherein the pharmaceutical composition comprises an effective dose of the anthocyanin extract; and the anthocyanin extract refers to an extract obtained from mature fruits of a zygophyllaceous nitraria plant and having a total anthocyanin content greater than 700 mg CGE/g and a total antioxidant capacity greater than 200 mg TE/g. Cytobiology and molecular biology studies prove that the anthocyanin extract has obvious protection effect to cardiomyocyte toxicity damage induced by anthracyclines and may be used for preventing and alleviating cardiotoxicity of an antharcyclines anticancer drug, thereby expanding a clinical application of the antharcyclines anticancer drug and relieving toxic and side effects brought by the antharcyclines anticancer drug to a patient and pain of a chemotherapy patient. And additionally, the raw material sources for the anthocyanin extract are wide, the cost is low and the use is safe.