A pet feces collection device comprising: a plate having a recess defined in a top edge of the plate and the recess being adapted to yield a tail of a pet, the plate being adapted to be located at a bottom of the pet, the plate having two positioning portions, and the recess located between the two positioning portions,, a through hole defined through the plate and being not in communication with the recess, the through hole of the plate being adapted to be aligned with anus of the pet; a left-leg belt and a right-leg belt connected to two corners of a lower portion of the plate, each of the left-leg belt and the right-leg belt having a connection member,, the two connection members, of the left-leg belt and the right-leg belt being adapted to extend between two rear legs, of the pet; wherein collection device further comprises a strip having two ends each of which is connected to one of the two positioning portions, of the plate, a middle portion of the strip extending through an adjustment unit to form an enclosed mounting portion and two restriction sections, the adjustment unit located between the mounting portion and the two restriction sections which are connected to the plate, a mounting area being defined by the mounting portion, a restriction area being defined between the adjustment unit, the two restriction sections and the plate; the connection members, of the left-leg belt and the right-leg belt being connected to the mounting portion of the strip, the restriction area being adapted to be mounted to the pet with the tail extending through the restriction area, the mounting area being pulled to be a triangular area, and wherein the plate has multiple clip portions located around the through hole so as to secure a periphery of an opening of a bag. a plate having a recess defined in a top edge of the plate and the recess being adapted to yield a tail of a pet, the plate being adapted to be located at a bottom of the pet, the plate having two positioning portions, and the recess located between the two positioning portions,, a through hole defined through the plate and being not in communication with the recess, the through hole of the plate being adapted to be aligned with anus of the pet; a left-leg belt and a right-leg belt connected to two corners of a lower portion of the plate, each of the left-leg belt and the right-leg belt having a connection member,, the two connection members, of the left-leg belt and the right-leg belt being adapted to extend between two rear legs, of the pet; wherein collection device further comprises a strip having two ends each of which is connected to one of the two positioning portions, of the plate, a middle portion of the strip extending through an adjustment unit to form an enclosed mounting portion and two restriction sections, the adjustment unit located between the mounting portion and the two restriction sections which are connected to the plate, a mounting area being defined by the mounting portion, a restriction area being defined between the adjustment unit, the two restriction sections and the plate; the connection members, of the left-leg belt and the right-leg belt being connected to the mounting portion of the strip, the restriction area being adapted to be mounted to the pet with the tail extending through the restriction area, the mounting area being pulled to be a triangular area, and wherein the plate has multiple clip portions located around the through hole so as to secure a periphery of an opening of a bag.