Normal calculation and posed relationship calibration of the system are the key technologies in stereoscopic deflectometry. For the normal calculation, the one-dimensional search method after stereo rectification is proposed on the basis of the polar line criterion, and the normal calculation is transformed into searching the minimum value of the normal angle. The gradient is obtained from the normal, and finally the mirror surface is restored from the gradient data by the radial basis interpolation function. For the system posed relationship calibration, the parallel mirror calibration method is proposed. This method only needs two parallel mirror images to determine the posed relationship of camera relative to screen, which makes the calibration process more free and flexible. The preliminary experiment verifies the feasibility of the proposed method.