从MonteCalor模拟和北京谱仪 (BESⅡ )所取的实验数据入手 ,分析了p和 p产生次级带电径迹和中性径迹的几率以及好径迹选择条件对这些次级径迹的去除情况、p在探测器中的能量损失和 p的湮没、p和 p在桶部簇射计数器中沉积能量的分布以及 3种不同的粒子鉴别方法的优劣 .给出了BES目前可以正确重建出的p和 p的动量的最小值和利用TOF和dE dx的联合信息鉴别p和 p的优越性 . Based on the experimental data from MonteCalor simulation and Beijing spectrometer (BES Ⅱ), we analyzed the probability of p and p generating secondary charged tracks and neutral tracks and the removal of these secondary tracks under the condition of good track selection , P loss of energy in the detector and annihilation of p, distribution of energy p and p deposition in the bucket shower counter, and the advantages and disadvantages of three different particle identification methods are given. The BES presently correctly reconstructed p and p of the minimum momentum and the use of TOF and dE dx combined information to identify the advantages of p and p.