The invention relates to the technical field of building, and discloses a shock-absorbing cart capable of expanding volume for a construction site. The shock-absorbing cart capable of expanding the volume includes a cart hopper, a bottom plate is connected to the bottom of the cart hopper, wheel hubs are disposed on the left side of the bottom of the cart hopper, and tires are connected to the periphery of the outer walls of the wheel hubs. A connecting rod communicates with the right side of the bottom plate in a penetrating mode, a universal wheel is mounted at the bottom of the connecting rod, and bolts are arranged on the middle position of the connecting rod from right to left. A handle is connected to the top of the connecting rod. Slide ways are installed on the inner wall of the cart hopper, slide rails are installed on the outer wall of the cart hopper, and the slide ways work with the slide rails in a cooperative mode, so that an inner hopper is drawn out of a cart hopper body in the case that the inner hopper is subjected to artificial external force; and through the action of limiting blocks, the volume between the inner hopper and the cart hopper reaches the maximum value, the purpose of expanding the volume of the cart hopper is achieved, manpower and energy wasted by a secondary transportation is avoided when a worker transports building materials, and the work efficiency of the worker is improved.