The invention discloses a preparation method of a novel isoquinoline medicine molecule with antibacterial activity and belongs to the technical field of synthesis of medicines. The key points of the technical scheme are characterized in that formulas are as shown in description. In the formulas, R is O or S. Compared with the prior art, the synthesis method is simple; the molecule is novel in structure and excellent in reaction effect repeatability, has inhibition effects on escherichia coli and staphylococcus aureus, is safe to human fibroblast, and is expected to be further popularized and applied.