The utility model relates to a rotary double-piston rotor machine, in whose cylinder block two nested rotary piston rotors are arranged and whose driving component is composed of a driving handle installed on a rotary shaft through a radial arm and a driving disc arranged correspondingly. The shaft line of the driving disc is parallel to the shaft line of the piston rotor and is e away from the shaft line of the piston rotor, making driving bodies and the driving handle form the relationship of eccentric drive, and three or four driving bodies are provided and are bar or column shapes. By adjusting the e value of the driving member, the condition of the relative differential motion can be controlled, when the piston rotates, making the volume of the working room vary to obtain different compression ratios. The utility model with the advantages of simple structure and the wide adjustable range is applicable to internal combustion engines, pneumatic motors, air pumps, etc.