Considering the limitation of small range of strapdown laser guided munition, the target distance and angle acquisition probabilities of terminal guided munition were studied by computer simulation method. The seeker line of sight model was established by seeker imaging principle and coordinate transformation. The analytical method of target acquisition probabilities was proposed to get the best boot time, and conducted the experiment by Monte Carlo method. The results showed that the target acquisition of terminal guided munition was more than 99.87%, the variation range of line of sight was reduced with the increasing angle, and it was mostly affected by disturbance of angle.