Abstract: To study the surface subsidence of non-principal section in a moving basin, to improve the application of non-principal section measured data during the inversion of predicted parameters, the T₃292 working face of Tangshan Mine is taken as the engineering background, and a combination of theoretical analysis, numerical simulation and field measurement is adopted. We propose a method for processing non-principal section measured data based on the probability integral method, and we use FLAC^3D to study the influence of non-principal section position parameters (intercept and slope) on the maximum subsidence value and influence radius. Finally, we obtain the predicted parameters based on the field measured data. The results show that: the maximum subsidence value and the influence radius change regularly when the position of the non-principal section changes. When the line intercept is reduced from 660 m to 0 m, the maximum sinking value increases from 97 mm to 114 mm, which increases by 17.4%; when the slope of the survey line is reduced from 1 to 0, the influence radius r_k is increased from 400 m to 586 m, which is an increase of 46.5%; finally, we can get the approximate value of the influence radius, r₀=558 m, by processing the measured data of the non-principal section of the T₃292 working face, which is 7% less than the measured result of the principal section. This non-principal section data processing method can be applied to the prediction of surface subsidence parameters in underground mining face mining.