Abstract: As a heat pipe occupying a place in the field of heat transfer, the PHP is widely used in electronic heat dissipation equipment, and regarded to be one of the heat dissipation components that have great development prospects under the conditions of extra high heat flow density and power consumption. With the maturity of nanotechnology, Nano fluid has also become an innovative research in the traditional field of heat dissipation and heat transfer. Therefore, it is extremely important to explore the change mechanism and change law of the operation and thermal characteristics of the pulsating heat pipe in different magnetic field environments. Through the use of an external magnetic field to strengthen the experimental research on the heat transfer of the nano-magnetic fluid pulsating heat pipe, a visualization experiment platform for heat transfer testing of the nano-magnetic fluid pulsating heat pipe was built. The temperature distribution and heat transfer rate of the plate-type pulsating heat pipe under the action of the magnetic field size of 25, 5, 1 and 0 mT and different magnetic field directions are respectively measured. The influence of factors such as nano-magnetic fluid, heat load power consumption, magnetic induction intensity and magnet placement position on its heat transfer performance is studied. The experimental results show that the use of Fe₃O₄/ethanol nanofluid as the working fluid can significantly enhance the heat transfer performance of the pulsating heat pipe under the action of a magnetic field. Especially under high heat flux loading, this can provide a reference for the working conditions of ultra-high heat flux density and power consumption.