Abstract: In order to solve high-speed data acquisition for rotating photoelectric encoder in the dynamic detection, the method of encoder angle data collection was proposed and the acquisition system of dynamic errors for absolute photoelectric encoder was designed. Firstly, it was proposed that the exact time of acquisition for error data was at the edge of data by the analysis of the exact time for the output of encoder. Secondly, the circuit was designed with FPGA and USB chips by the analysis of quantity, acquisition speed and transmission speed of error data. Finally, the computer software finished the calculation, displaying and printing. By the results of experiment, the system can collect the error data of rapid rotating encoder accurately, meanwhile suited for the detection of the dynamic characteristics for small absolute optical encoder. This system can achieve the data acquisition of 16 bits photoelectric encoder below the speed of 90 r/min accurately.