The paper presents results of formation of expanding plasma by combining laser‐produced plasma with an external strong magnetic field. The plasma was generated by means of a Nd‐glass laser which was focused on a solid target located on the axis of a single‐turn coil providing magnetic field of up to 50 T. Spatial characteristics of the dynamics of interaction of the plasma with the magnetic field were registered by means of a three‐frame interferometry. For registration and analysis of interferograms, CCD cameras and a multichannel image acquisition system were used. An interesting influence of the strong magnetic field on the plasma dynamics and shape was observed. Preliminary results of numerical modelling are compared with the experimental data.