Abstract: FBMC technology has become an effective technology for 5G networks, because it does not require a cyclic prefix, has less out-of-band energy leakage, and can flexibly utilize spectrum fragmentation and other advantages. However, an important issue in the FBMC system is the peak to average power ratio (PAPR). In a filter bank multicarrier system, the partial transfer sequence (PTS) method is usually used to reduce the peak-to-average power ratio (PAPR). Since this method needs to carry side band information in the transmission process, it may reduce the spectrum utilization. Aiming at the above problem, this paper makes some improvements in two aspects based on the PTS method. The first one is on the searching for the best phase factor and propose a new multi-loop search method such that it can avoid the repeated search and reduce the computational complexity. The second one is to introduce an improved constellation extension (ACE) method, by which the receiver can quickly demodulate the original data without the need for side band information, thereby improving the spectrum utilization and sacrificing a small amount of PAPR. Finally, the effectiveness of the two improved schemes is verified by calculations and simulations.