A biaxial magnetoresistive angle sensor with a corresponding calibration method for magnetic field error correction, comprising two single-axis magnetoresistive angle sensors for detecting an external magnetic field in an X-axis direction and a Y-axis direction that are perpendicular to each other, a unit for calculating a vector magnitude of the voltage outputs of the single-axis magnetoresistive angle sensors along the X axis and the Y axis in real time, a unit for calculating a difference between a known calibration vector magnitude and the measured vector magnitude, a unit for dividing the difference by the square root of 2 in order to calculate an error signal, a unit for adding the error signal to the X-axis output and the Y-axis output respectively or subtracting the error signal from the X-axis output and the Y-axis output in order to calculate the calibrated output signals of the X-axis and the Y-axis angle sensors, a unit for calculating an arc tangent of a factor obtained by dividing the calibrated Y-axis output signal by the calibrated X-axis output signal to provide a rotation angle of the external magnetic field. This method for applying the magnetic field error calibration to the biaxial magnetoresistive angle sensor reduces the measurement error and expands the magnetic field application range in addition to improving the measurement precision in a high magnetic field.