A picking ladder cart with a synchronized brake is provided, which includes a frame, a plurality of wheels, a ladder, and a stopper. The ladder is pivotally connected to a side of the frame, wherein the ladder is pivotally movable between a first position and a second position. The ladder includes two side rails and a plurality of steps, which are connected between the two side rails. The stopper has a first end and, a second end. When the ladder is moved to the second position, one of the plurality of steps, which is arranged at the lowest position among the steps, abuts against the second end of the stopper, which causes the stopper to contact one of the wheels. When an operator steps on the ladder of the picking ladder cart, the lowest step drives the stopper to abut against one of the wheels.