The invention discloses a semiactive/active composite control suspension without an external power source and a control method thereof, belonging to the field of automobiles. A hydraulic cylinder and a spring are connected in parallel and then connected between sprung mass and unsprung mass, and each oil way comprises a tank, a pressurizing package, a solenoid electric valve, an energy-regenerative power regulator and an energy accumulator; a control unit calculates the suspension control force after receiving the suspension state and the energy state information of the energy accumulator fedback by a speed and acceleration sensor group and a pressure sensor; when the control force and the speed of the sprung mass relative to the unsprung mass are in opposite directions, a semiactive energy feedback working mode is activated, and vibration energy between suspensions is converted to hydraulic energy and is stored in the energy accumulator for later use; and when the control force and the speed of the sprung mass relative to the unsprung mass are in the same direction, an active damping working mode is activated, the hydraulic energy obtained in the semiactive energy feedback working mode is input to the suspensions to realize the active damping without an external power source, and the suspensions have reliable performance and long service life.