Phloroglucinol compounds isolated from Dryopteris fragrans (L.) Schott showed a variety of biological activities, such as anticancer and anti-inflammatory. In this study, we have made a number of modifications around the scaffold of phloroglucinol and synthesized phloroglucinol derivatives A1–A9, B1–B9, and C1–C3. We synthesized these compounds and investigated their effect on four human cancer cell lines (A-549, MCF-7, Hela, HepG2 cell lines) via MTT assay in vitro. The results revealed that all compounds exhibited certain antiproliferative activities on cancer cell lines and excellent inhibitory effects on MCF-7, in which compound C2 was the best with the IC₅₀ value of 18.49 μM, exceeding that of 5-fluorouracil. Moreover, the cell apoptosis test showed that compound C2 induced apoptosis in a concentration-dependent manner. Furthermore, the results of molecular docking analysis explained the probable interaction between the active compounds and active sites of target protein 4I22 and 1OG5.