Abstract:The influence of observation precision to inversion results is studied from singular value, the distribution of data and a priori information of the inversion model. To take the reciprocal of the shortest distance between observation and the subdivision fault for weight, the model considering observation precision is established. On the basis of the dilocation model, the velocity of Longmenshan fault is calculated by GA. The results show that the data out of singular values, with the model considering observation precision, on the premise of reasonable a priori information, are stable and reliable.