The invention provides a small-sized variable crawler type search and rescue robot, comprising a body, a crawler travelling device, a communication device and a signal acquisition device, wherein the body is a carrier for the crawler travelling device, the communication device and the signal acquisition device; the crawler travelling device comprises a retractable crawler, a driving wheel and a retractor device; the retractor device is a slipper rocker mechanism consisting of two movable driven wheels, two fixed driven wheels and two linear push rods; the driving wheels are driven by driving shafts on the body, a linear push rod motor is taken as a slider and drives rockers and the movable driven wheels thereon to rotate around the fixed driven wheels so as to drive the crawler to stretch and shrink, thus forming a certain angle in the forward to backward direction of the crawler. The robot of the invention has small volume and flexible movement and can run forwards and backwards and turn in narrow space. The variable crawler can form certain angles in the forward to backward direction, thereby being beneficial to realizing obstacle detouring, reducing the volume of the crawler type search and rescue robot and improving the running speed of the robot.