A method for reducing errors in the measurement of temperature by magnetic resonance, for use in magnetic resonance imaging-guided HIFU equipment, includes acquiring an MR phase image, as a reference image, before heating an area to be heated with the HIFU equipment; acquiring another MR phase image, as a heated image, during or after the heating by the HIFU equipment; and calculating the temperature change in the heated area according to said heated image and said reference image; and making compensation to said temperature change according to the change in the magnetic field caused by the position change of an ultrasonic transducer in said HIFU equipment. The method can reduce significantly the temperature errors resulting from the position changes of the ultrasonic transducer.