为了得到真实的裂变径迹封闭长度分布，需要对重离子径迹密度、孔径及裂变径迹长度进行几率归一修正。对重离子蚀刻径迹与裂变径迹相重叠的几率进行了理论计算及MonteCarlo模拟。 In order to get the true closure length distribution of fission track, the probability of heavy ion track density, aperture and fission track length need to be corrected. The theoretical calculation and Monte Carlo simulation of the overlap probability of heavy ion etching track and fission track are carried out.