To solve the directionality of spatial magnetic field measurement , two schemes including three-dimensional measurement and simultaneous measurement of transverse, longitudinal components are proposed. The simulation and calculation of three crystals (TbY)IG,Ce∶YIG and YIG by Jones matrix are carried out, and the directionality of magnetooptic glass of MR4 is tested. Both theoretical and experimental results prove the feasibility of the first scheme. For the second scheme the relationship between azimuth angle, ellipticity of the elliptical polarization light and Faraday rotation angle, magnetic linear birefringence is gained, which confirms the feasibility of the second scheme.