The fission BPF (FBPF) algorithm do solved the problem of sample impoverishment in general SIR method. But it also increased some compute burden than SIR; meanwhile it has the equivalent estimate precision with SIR. For the purpose of reduce some processing time or increase the estimating precision. This article analysis the performance of FBPF algorithm in detail, and based on the analysis result proposed some improved methods to achieve the purpose aforementioned. Finally we give a simulation example which certifies the proposed methods do working well.