For on-line real time performance evaluation of an adaptive optics system, an embedded processing platform based on FPGA and DSP is proposed and designed, in which the FPGA is a co-processor for the high-speed data buffer, and the DSP is a main processor for the later complex signal processing. According to the closed-loop data of residual slope detected by Hartmann wavefront sensor, the on-line evaluation of performance parameters of an adaptive optics system is realized on this proposed platform, including point spread function, Strehl ratio, full width half maximum and modulation transfer function. The results indicate that the error levels of point spread function, Strehl ratio, full width half maximum are 10-11, 10-3, 10-4 times as diffraction limit and 10-4, respectively. As well as highly operational precision, this embedded processing platform has a simple structure, which is good for integration, and strong commonality.