The precision measurement network control method is based on the plane coordinates of the line and the elevation of the railway line alignment control method. According to China's track precision control measurement system and the principle of the precision measurement network control method, the sources of error analysis of the precision measurement network control method mainly include two aspects of three-dimensional adjustment error and point change error. The results of calculating the plane coordinates, elevation error, and track smoothness index of the measured station and adjacent stations when the CPⅢ points change at different positions and different numbers show that the coordinate error of the measuring station increases with the increase of CPⅢ point coordinate change. The closer the control point is to the measured station, the greater the impact of its change on the coordinates of the measured station is; and the changes of the control point farther away from the measured station are not sensitive to the influence of the station coordinates; the maximum value of the coordinate error of the station are 1.732，1.668，1.626 mm respectively; the maximum coordinate error of adjacent stations are 1.500，1.397，1.343 mm；among track irregularity index, the largest error is the track direction, fol lowed by the gauge and level, the smallest error is the height; When the coordinate change of the nearest CPⅢpoint from the station is 1.0 mm in each direction，the maximum values of track pitch，level，height，and track direction errors are 0.559，0.534，0.479，0.582 mm，respectively.