In this paper , the factor which affects the bit error of high speed air-ground date transmitting system IS analyzed , and the means of RS codes resolute IS put forward , On the basis of expatiating on the RS codes principle , the software flow chart IS glven. Expenments reveal that the capac1ty of correcting random error and burst error is better. Accordingly , RS codes strengthens the error bolerance and anti-interference capacity of the system and satisfies the bit error probability demands. .