A magnetic shielding room is designed in order to evaluate the magnetic shielding effect on low-frequency magnetic fields. A kind of shielding scheme is proposed，in which the shielding effect is studied under the joint influence of static magnetic field and alternating magnetic field. The experimental results show that for the proposed electromagnetic shielding room, indoor static magnetic field B≤200 nT，50 Hz AC magnetic interference<0.10 μT，greater than 100 kHz AC magnetic shielding factor S≥1 000，which meets the practical requirements of the magnetic sensor system. This work can provide a necessary theoretical basis for the shielding effect evaluation of shielding room.