The invention relates to a motor insulating bearing device and a manufacturing method thereof. The bearing device is characterized in that an insulating bushing is positioned at a circumference part between a bearing pedestal and a motor bearing, insulating space rings are arranged between the end of the insulating bushing and the motor bearing and an outer bearing cover and between the end thereof and an inner bearing cover, and a gap is left between the insulating space ring and the insulating bushing. The motor insulating bearing device is manufactured by a unique method, the formation of rotor axial current loop is prevented effectively and the electric corrosion damage of the motor bearing is avoided, thereby ensuring the reliable operation of the motor, prolonging the service life of the motor and decreasing the reactive power loss of the electric energy at the same time; the motor insulating bearing device has the advantages of reasonable structure design, reliable operational performance and convenient installation and maintenance, etc.