In order to solve the contradiction between the disc size and resolution, and to attain the high response speed, a new photoelectric absolute angular encoder is proposed based on a single-track coded disc and a linear detector. A new single-track absolute coded disc is used in the encoder. The encoded units are directly carved on one track. The image of coded disc is magnified by the imaging lens, and received by the linear detector. The FPGA control circuit sends the data of image to the computer for data processing. An integrated 7 bits binary code is obtained by image processing and the subdivision code unit is gained by pixel subdivision technique respectively, which are both contributed to the angular information. An absolute angular encoder, which contains a diameter of 40 millimeter code disc, is designed based on the technique. Its resolution can reach 15 bit.