In the early days, there were mainly two kinds of parallel gun layouts: (1) straight car versus transverse car (2) transverse car versus straight car. With the development of chess, in the mid-1970s. There has been a new pattern of slow through train and slow first move. The offensive and defensive tactics of both sides are more colorful, and various new formations emerge one after another, which greatly enriches the offensive and defensive contents of the parallel gun layout system.