Ultrashort throw projector (UTP) technology has been a challenging research focus in the fields of large field of view and short-distance projection. In this paper, we propose a design method for a curved-target UTP based on image precorrection. A predistortion method (<1p i x e l) using a radial basis function is presented to effectively correct irregular distortion. A grayscale precorrection method is used to address uneven illumination distribution. We provide a UTP design example and verify the correction methods using two different curved targets (aspherical and freeform), demonstrating effective distortion correction (<1%) and illumination uniformity (>90%). The structure similarity index measure for the projection images shows close or greater than 0.9 correlation.