H-Frame fixed electromagnets have a fixed magnetic field air gap, double yoke structure with a closed magnetic circuit, and a horizontal magnetic field direction. The pole can be changed to fix a new air gap. The H-Frame fixed electromagnet has excellent rigidity and stability and is suitable for experimental research on the stability of the magnetic field’s uniformity. It is also quite suitable for Hall effect research, magnetoresistance effect research, and hysteresis retraction research. The H-Frame fixed electromagnet can also be used as a torque magnetometer, force method magnetometer, magnetic susceptibility measurement device, magnetic material measurement device, etc. It is especially suitable for use as a vibrating sample magnetometer or in nuclear magnetic resonance application of high-precision instruments such as magnetometers.