A fast recognition method of Reed-Solomon(RS) code based on check-sum is proposed to reduce the computation and improve the recognition speed. Firstly, the cyclic code with the primitive element of each possible finite field as the unique code root is constructed. The check-sum is calculated by using the binary check matrix of the cyclic code and is compared with the threshold so as to recognize the coding field. Then, the cyclic code with each element of the coding field as the unique code root is constructed. And the check-sum corresponding to each element is calculated. Finally, the generator polynomial is recognized based on the continuity of RS code roots. Compared with the spectral cumulant method, the proposed method improves the recognition speed by about one order of magnitude and the recognition performance by 0.1 dB; while at the error rate of 0.001, the amount of data required to achieve the same recognition performance is about 1/3 of the original method. Simulation results show that the proposed method is much better than the spectral cumulant method in terms of recognition speed and data requirement.