To increase the penetration probability of anti-ship missile, an effective way is to adopt saturation attack, which requires that multiple missiles to arrive at the target simultaneously.However, the actual flight time of missile is a random variable, which may cause differences in the arrival time of each missile at the target, thus influencing the cooperative combat efficiency of multiple missiles.Based on the time difference model for anti-ship missile saturation attack, such distribution characteristics as probability distribution function, probability density function, mathematical expectation and mean square error of time difference in anti-ship missile saturation attack are given in three respective cases that the actual flight time of missile complies with uniform, exponential and normal distributions.Finally, an analysis and a summary are made through an example, to reach a conclusion that the randomness of actual flight time of missile has a considerable influence on the time difference in anti-ship missile saturation attack, which needs to be taken seriously.