Rail interval adjuster and adjusting head thereof

The invention discloses a rail interval adjuster and an adjusting head thereof. The rail interval adjuster comprises a square mounting block and an abutting block, an abutting face opposite to the side wall of a rail is arranged on the mounting block, a triggering groove is formed in the abutting face, a main passage is arranged in the mounting block and penetrates the side wall, adjacent to the abutting face, of the mounting block, the triggering groove is communicated with the inside of the main passage, a triggering block is slidably arranged in the triggering groove, and the end face, awayfrom the main passage, of the triggering block protrudes out of the abutting face; the abutting block is slidably connected in the main passage, two ends of the abutting block are an abutting end protruding outside the mounting block and a control end positioned in the main passage, one side face of the abutting end is flush with the abutting face, and a first elastic spring is connected betweenthe abutting end and the m