The invention discloses a compound injection preparation for treating cardiovascular and cerebrovascular diseases and a preparation method thereof. The preparation method comprises the following steps of: taking alprostadil and edaravone as active pharmaceutical ingredients, and compounding the alprostadil and the edaravone according to a certain ratio to form a certain injection preparation. With the adoption of the compound injection preparation, heart vessels or brain vessels can be effectively dilated, the chronic arterial occlusive diseases, caused by thromboangiitis obliterans, diabetes and the like, can be effectively treated, and meanwhile, the pain generated in the conventional injection of an alprostadil preparation can be remarkably abated due to the adoption of the compound preparation of the alprostadil and the edaravone.