Based on the equations of the optical transform, phase errors of the holographic lens used in a transform caused by space-transverse-modulation is analysed, and a method of computer generated hologram combined with optical holography is proposed to generate a 2-dimensional (2-D) holographic lens suitable for 2-D transform. The 2-D Walah-Hadamard transform in 32-sequenoe is optically realized. The experimental results are in agreement with the theoretical calculations.