Abstract: A pin puller is revealed. The pin puller includes a cylinder mounted with an actuating rod therein. A front end of the actuating rod is connected to and fixed on a pin connection unit. The pin connection unit is fitted over and connected to one end part of a positioning pin while a binding sleeve is disposed around the pin connection unit. The other end part of the positioning pin is mounted and connected to a fixing unit for pin-disassembling or a fixing unit for pin-assembling for driving the cylinder to move the actuating rod. The positioning pin is further pulled to be disassembled or assembled by the pin connection unit. Thereby the pin puller has simpler structure. Thus the manufacturing cost is lowered and the pin puller is having simpler structure and more convenient in operation and use.