A blood magnetic stimulation device includes a magnetic stimulation unit that has a stimulating coil for being connected to a blood delivering unit or directly worn by a user. The stimulating coil is further connected to a pulse-generating unit that outputs a pulse current to excite the stimulating coil, so as to use electromagnetic pulses to apply strong yet transient magnetic stimulation to blood passing through the magnetic stimulation unit or to blood in the user's subcutaneous vessels, thereby providing magnetic treatment for viremian and related diseases. As compared to the existing blood treating devices, the magnetic stimulation provided by the blood magnetic stimulation device incurs no sharp pain and uncomfortableness, and is safer and more acceptable to patients.