The invention provides a device used for preparing an ecological board formaldehyde release guide groove. The device includes a first conveying belt; the front end of the first conveying belt is provided with a first press device used for impressing first grooves on a pair of side faces of an ecological board; the rear end of the first conveying belt is provided with a first board pushing device used for aligning the ecological board and pushing the ecological board to a second conveying belt; the conveying direction of the second conveying belt is vertical to the conveying direction of the first conveying belt; the front end of the second conveying belt is provided with a second board pushing device used for aligning the ecological board; and the end of the second conveying belt is provided with a second press device used for impressing second grooves on the other pair of side faces of the ecological board. The ecological board can accelerate to release formaldehyde by opening formaldehyde release guide grooves on the side face of the solid wood layer in the middle of the ecological board through the press devices, so that formaldehyde content in boards can be lowered, and harm topeople brought by the formaldehyde can be reduced.