Development of adjuvant chemotherapy drugs against drug-resistant lung cancer cells is necessary. The use of non-toxic adjuvant natural product combined with chemotherapy drugs will be an important treatment mode in the future. The purpose of the study investigates that fucoidan enhances chemotherapy drug poisoning drug-resistant lung cancer cell. Drug-resistant lung cancer cells are established in the study. Cell culture, MTT assay, wound healing assay, gelatin zymography assay, DNA fragmentation assay, apoptosis assay, reverse transcription polymerase chain reaction (RT-PCR) western blot analysis was adopted. The results showed that fucoidan synergized with doxorubicin increased efficacy of poisoning drug-resistant lung cancer cells and enhanced the ability of doxorubicin to inhibit the migration of drug-resistant lung cancer cells. It was observed that fucoidan synergized with doxorubicin induced the increase of apoptosis and inhibited expression of MMP-9, LC3, Beclin-1 and β-catenin in drug-resistant lung cancer cells. Fucoidan synergized with doxorubicin significantly inhibited proliferation, migration and metastasis of drug-resistant lung cancer cells. Fucoidan strengthened doxorubicin to induce apoptosis and autophagy of drug-resistant lung cancer cells. This study confirms that the combined use of fucoidan and chemotherapeutic drugs can effectively poison drug-resistant lung cancer cells.