The invention provides a preparation method of porphyrin photosensitizer and anticarcinogen diad, relates to a preparation method of the diad and solves the technical problems that the porphyrin photosensitizers cannot kill all cancer cells under the light irradiation, the targeting of the anticarcinogen is insufficient, and toxic or side effects are generated. The method comprises the following steps of: 1, preparing midbodies; and 2, preparing the porphyrin photosensitizer and anticarcinogen diad. Because porphyrin and the metal complex compounds thereof have special affinity on the cancer cells, the photosensitizers of 4-hydroxyphenyl porphyrin and anticarcinogen are prepared into the diad, the affinity of the porphyrin on the cancer cells is utilized, so the targeting of the anticarcinogen can be improved, the anti-cancer capability is improved, and in addition, the toxic or side effect is reduced. The anti-cancer effect of the anticarcinogen overcomes the defect of insufficient anti-cancer capability of the porphyrin photosensitizer. Under the conditions of light illumination and dark light, two different anti-cancer mechanisms realize the cooperative effect, the advantage complementation of the anti-cancer effects of the two compounds is realized, the toxic or side effects are reduced under the use condition of the same quantity, and the anti-cancer capability is improved.