Different degrees of anti-tumor effect by hydrogen release from high purity magnesium (Mg) through galvanic corrosion induced by dissimilar metals can be achieved. High-purity Mg was connected to Mg alloy AZ91, pure titanium TA2 and stainless steel 316L respectively. The open circuit potential and polarization curve of high-purity Mg were measured by electrochemical workstation in PBS solution under 37 ℃ water bath condition, and hydrogen evolution curve was measured by immersion experiment under the same conditions. Finally, the biological effects of different amounts of hydrogen released by high-purity Mg under the regulation of dissimilar metals on Cal-62 tumor cell line were studied in vitro, including the effects of hydrogen on proliferation, apoptosis and cycle of tumor cells. It was found that the three metals cause different degrees of polarization. The open circuit potential, corrosion potential and corrosion current density of high purity Mg all increased with the increase of polarization, which caused more significant hydrogen evolution in the meantime. 48 hours after the release of hydrogen, the proliferation of Cal-62 tumor cells was significantly inhibited, up to 55%. On the one hand, hydrogen could promote apoptosis of tumor cells. On the other hand, hydrogen could increase the proportion of cells in G0/G1 phase and decrease the proportion of cells in S phase, arresting the cell cycle of tumor cells in G0/G1 phase. As the amount of hydrogen released increased, the effects of promoting apoptosis and arresting the cell cycle were more significant. Under the control of these three dissimilar metals, Mg can accelerate the release of more hydrogen through different degrees of corrosion, and achieve a more significant anti-tumor effect.