The invention discloses a united medicine used for treating tumors, comprising manganoporphyrin, sodium cromoglyate and one or a plurality of optional medicinal carriers, or comprising the manganoporphyrin, dichloroacetic acid or pharmaceutically acceptable salt thereof and one or a plurality of optional medicinal carriers, or comprising the manganoporphyrin, any anti-tumor medicine and one or a plurality of optional medicinal carriers. The inventor of the application carries out a series of relevant experimental researches; and the experiments prove that by uniting the manganoporphyrin and the medicines which can be united for use as the medicine, the curative effect of the tumors can be enhanced, the toxicity of the medicine can be reduced, the survival time of experimental animals is prolonged, and an unlooked-for effect is obtained.