The invention discloses an ahead-of-time stopping method of a 
low complexity LDPC code weighting bit flipping decoding 
algorithm. The method includes the steps that S1, initializing is conducted; S2, the syndrome s is calculated through z, wherein the s={s1, ...sm, ...sM}= zH<T>, sm=mod(sigma n<A (m) zn, 2), the expression of the sm is shown in the specification; S3, when the s is equal to zero, iteration is stopped, and decoding output is z; when the s is not equal to zero, if k>=Kmax, decoding fails, and decoding is over; if k<Kmax and k=k+1, the flipping function {En, 1<=n<=N} of each information node is calculated; the maximum value (please see the specification for the formula) of the flipping function is solved, and if MAX<0, decoding is over; otherwise, the z is updated, and iteration continues. According to the ahead-of-time stopping method of the 
low complexity LDPC code weighting bit flipping decoding 
algorithm, after the flipping function {En, 1<=n<=N} of each information node is obtained through calculation, the maximum value of the flipping function is solved, if MAX<0, the iterative process is stopped directly, wherein the expression of the MAX is shown in the specification, and otherwise iteration still continues according to the original steps; the non-error correction frame decoding process can be discovered and stopped in time, waste of hardware resources is avoided, and decoding time 
delay is lowered. 
Simulation results show that under the condition that the 
bit error rate and the 
frame error rate basically remain unchanged, the average iterations of the weighting bit flipping decoding 
algorithm can be greatly decreased, and therefore the 
system time 
delay and the implementation complexity are lowered.