Abstract: This article used wave number space in the calculation of the gravity gradient,the introduction of B.M derivative filter factor to suppress the error amplification process.Model experiments show that the spatial parameters is closer to the actual figure；Filtering the harmonic number N and the choice of filter factor index n to suppress interference sources in the complex terrain,and describe the relationship between N and n;Gravity gradient method is usually the peak and trough for V_zz choice with the subjectivity of human experience，Author think by V_zz and V_xz of the lateral line along the horizontal direction of the derivative position to accurately determine the level turning point，using gravity anomalies curves and geological data to eliminate meaningless peaks and troughs，to reduce the computational workload.

Key words: Gravity gradient in wave mumber space, Higher derivative, Songliao basin, B.M derivative filter factor