The invention discloses a modeling method for a virtual well of a target layer of a horizontal well. Based on a conventional modeling method, through addition of the virtual well, calibration points on the trajectory of the horizontal well are increased, and the distance between the calibration points is shortened. Meanwhile, calibration of original individual-well data is extended to calculation of double-well point or multi-well-point data, so that the calibration accuracy is improved. The reliability of target layer modeling is guaranteed, expected regulation on the trajectory with drilling is effectively supported, and the drilling rate of the horizontal well is improved.