Method of vacuum deposition and technique of crystallization treatment without oxidation are adopted in the invention. The method includes following steps: mixing selected Ni, Co in high purity according to proportion l:2.3; carrying out film coating by vaporization; when vacuum degree being as 1.0X10 to the power -6 torr, heating desk for carrying sheets for 20 minutes to reach 450 deg.C, and at constant temperature for 5 minutes; controlling speed of vaporizing Ni, Co materials at 0.05 nano/sec. and thickness under 30 nano; through crystallization treatment without oxidation, anisotropic magnetic thin film is obtained. Magnetic sensor in micro power dissipation is produced after semiconductor planar technology being carried out.