The projection method obtains a circular-screen projection surface by dividing a visual platform to be projected, arranges each optical machine to be arranged according to maximum optical path distance information that each optical machine to be arranged projects an image onto each circular-screen projection surface to obtain a first projection coverage range, and adjusts the first projection coverage range according to setting parameters corresponding to each optical machine to be arranged and in accordance with a preset projection surface to obtain a second projection coverage range. The projection method calculates geometric parameters and the second projection coverage range of each optical machine to be arranged to obtain a spatial position and a rotation angle range of each optical machine to be arranged.