The invention discloses a rotary system and method for vehicle compartment volume measurement. The rotary system comprises a base, a stand, a rotary cross beam, a rotary motor, a balance block, a travelling trolley, a variable frequency motor, a control box and an upper computer; the lower end of the stand is fixed to the base, the rotary motor is fixed to the top end of the stand, one end of the rotary cross beam fixedly sleeves the rotary shaft of the rotary motor, the balance block and the variable frequency motor are fixedly mounted at a balance extension end of the rotary cross beam, the travelling trolley is disposed on the rotary cross beam and is connected through a chain that meshes between a sprocket and a driving gear of the variable frequency motor, and a first laser scanner and a second laser scanner are also provided below the travelling vehicle, and the variable frequency motor, the rotary motor, the first laser scanner and the second laser scanner are electrically connected respectively with the control box. The measurement system and method according to the invention provide quick measurement for the volume of cargoes in a vehicle compartment, with small measurement error and good control convenience.