A push and draw chain for realizing rigid and flexible conversion is used for 'telescopic arm' required by long distance work. The chain includes chain elements, control pins, fixed pins, pressure covers, springs, bolt shaft holes and screws; wherein the rectangle chain elements are same in structure and can be jointed with each other recur to the flanges and grooves on the two longitudinal sides; the jointed chain elements can rotate around a bolt shaft revolved into the bolt shaft hole and the screw; the head of the control pin is protruding under the function of spring force; the < shape groove is separated from engagement with the < shape head part of the fixed pin, the conical head of the fixed pin is pressed into the conical hole of adjacent chain element to make it can not rotate with each other and to 'rigid' status; after the control pin is pressed into the holes, the fixed pin is under the function of the spring force, and its < shape heat is pressed into the < shape groove of the control pin, the conical head part of the fixed pin will separate from the engagement with the conical hole of the adjacent chain element, the chain elements can rotate freely and at 'flexible' status. The 'rigid' status of the whole push and draw chain is independent of the force direction.