Reliability-Based hybrid automatic repeat request (RB-HARQ) scheme can reduce the amount of retransmission bits by retransmitting the most unreliable bits. In this work, we provide an approximate method for calculating the BER of retransmission frame of RB-HARQ scheme. Further, in order to lower the feedback overhead, we propose Segmented Reliability-Based HARQ (SRB-HARQ), choosing the most unreliable bit in every segment to retransmit, and the performance analysis is also given for SRB-HARQ. Both the theoretical analysis and simulation results can prove that the SRB-HARQ can reduce the feedback overhead and provide similar frame error rate (FER) of RB-HARQ at the same time.