A dog droppings catcher includes a fixing board and a droppings bag. The fixing board has an end forming a coupling section and an opposite end forming an opening closure section. The droppings bag has an opening and an interior receiving space and is combinable with the coupling section. The coupling section includes a through hole in communication with the opening of the droppings bag. The device can be easily carried by a user or temporarily hung on a leash of a dog. Before dog droppings fall onto the ground, the user may hold the opening closure section in such a way as to allow the dog dropping to pass through the through hole of the coupling section into the droppings bag. The opening closure section is then folded toward the coupling section to get laid flat on the coupling section for closing the through hole of the coupling section.