A new method for the wavefront measurement of high power laser diode array with large dynamic ranges is presented. The wavefront sensor has a large dynamic range of −π/2 to π/2 and high precision on the measured wavefront slopes (±1′). According to the measurements of the slopes and intensity of the high power laser diode array, complex amplitudes can be obtained and the wavefront can be reconstructed. The reconstructed wavefront of high power laser diode array can be used in designing a laser beam shaping system in future work.