Aiming at the path elimination error issue during path decision in successive cancellation list (SCL) decoding algorithm of polar codes, an improved SCL flip(SCLF) based on the flip set of the information bit metric(IBMFS-SCLF) decoding algorithm is proposed. The algorithm exploits the structural correlation between adjacent Rate-1 subcodes of varying lengths and their associated decoding failure patterns. Through quantitative analysis of this relationship, the information bit metric within longer Rate-1 subcodes is calculated to systematically identify error-prone bit positions. These positions are added to the critical set, which is subsequently sorted by ascending reliability metric to construct the IBMFS. Simulation results demonstrate that the proposed IBMFS-SCLF decoding algorithm has the superior error performance and lower complexity compared to SCLF based on the revised critical set(RCS-SCLF) decoding algorithm and SCLF based on the improved critical set(ICS-SCLF) decoding algorithm.