Single/continuous dual firing mode trigger structure for air nailing gun

A single/continuous dual firing mode trigger structure installed in an air nailing gun and adapted to fire said nailing gun, comprising:

• gun body having a handle, a firing valve installed in said handle, said firing valve being of a two-step firing design that does not fire said air nailing gun when forced to a first step position, and achieves a firing action when forced further to a second step position;
• a trigger holder, said trigger holder having a pivot hole;
• a safety link axially slidably mounted in muzzle of said gun body, said safety link having a curved rear end extended to the inside of said trigger holder;
• a trigger assembly pivoted to said pivot hole of said trigger holder and adapted to drive said firing valve to fire said air nailing gun;
• Wherein said trigger assembly comprises a main trigger member pivoted to the pivot hole of said trigger holder, a pivot shaft, which pivots said main trigger member to the pivot hole of said trigger holder, said pivot shaft having a longitudinal cut plane, and a supplementary trigger member, said supplementary trigger member having a tail movably pivoted to the inside of said main trigger member and a head to be stopped at said pivot shaft.