Increasing the heat transfer rate in various industries to improve the efficiency of equipment, prevent damage to parts and reduce costs is one of the essential discussions in the industry. In this research, an active heat sink and gallinsten liquid metal is considered as the working fluid. The effect of applying the magnetic field in the Y direction (perpendicular to the flow axis) to the thermal well has caused the creation of a force against the flow direction called the Lorentz force, which has caused the M-shaped velocity distribution. This type of velocity distribution has caused an increase in the flow velocity in the vicinity of the walls and a decrease in the flow velocity in the central line of the microchannel. By applying an alternating magnetic field in the X direction to the thermal well, the velocity distribution has become flat. The results showed that the effect of direct and alternating magnetic field has improved Nusselt number. By applying an alternating magnetic field in the Y direction, the Nusselt number is improved by 38% and by applying a magnetic field in the X direction, the Nusselt number is improved by 11.62%. The increase in the speed gradient resulting from the application of direct and alternating magnetic field has also increased the friction coefficient. In this research, by examining the phase difference of magnetic and electric fields from zero to 90 degrees, it was shown that the pressure drop and the friction coefficient resulting from the magnetic field have decreased.