Billiards is a kind of international widely popular elegant indoors sports event, is a kind of using cue to stroke on the table, relying on calculation ace to define competition result indoors recreational sports event. Billiards not only can be regarded as competition event, but also it can also be regarded as rigid body in mechanical researches, billiards as a rigid body exercise typical example, cue ball and object ball collision process conform to rigid body exercise basic rules. Billiards collision process conforms to rigid body collision perfect elastic collision process. In case that normally strokes cue ball, cue ball not collideswith billiards table side after it colliding with object ball, applies theoretical mechanical knowledge and physics collision rules, it can make anticipation on cue ball sports trajectory. This paper, after analyzing cue ball force status after colliding, itmakes qualitative and quantitative analysis of cue ball sports trajectory. Results show mass center speed gets larger, rotational angular speed gets smaller, and then cue ball trajectorywill get closer to cue ball and object ball common tangent.