Extension spring fixing device

The invention discloses an extension spring fixing device. The extension spring fixing device comprises a bottom plate, and a pedal support vertically arranged on the bottom plate; the middle part ofthe pedal support is provided with a through rectangular hole in the transverse direction; an extension spring tightness adjusting device is arranged in the through rectangular hole; the upper part ofthe pedal support is fixedly connected with a transverse shaft; the transverse shaft is rotatingly connected with a pedal connecting seat; one side of the pedal connecting seat is designed to projectoutward to form a connecting sleeve; first tooth marks are formed on the external surface of the connecting sleeve; the connecting sleeve is sleeved with an extension spring connecting ring; the upper part of the extension spring connecting ring is provided with an opening, and the opening can be locked using a bolt; second tooth marks matching the first tooth marks are formed on the internal surface of the extension sprin