The invention discloses a combined recycling and comprehensive utilizing apparatus and method of inertia energy of car wheels and vibration energy of a suspension, belonging to the technical field of car energy conservation and emission reduction. The method comprises the following steps: first connecting a plunger pump between a sprung mass and an unsprung mass of a car suspension in a floating manner, and driving a hydraulic pump to work by using vibration displacement generated when a car drives on a fluctuated pavement; additionally fixing an inner gear ring on a car wheel hub, when the car wheel rotates, enabling power to be sped up by virtue of an inner gear transmission machine, and directly driving the hydraulic pump/hydraulic motor to work; when a car brakes and decelerates, rapidly converting a great amount of inertia energy of the wheel to hydraulic energy to be stored; and when the car is started and sped up, directly providing two portions of hydraulic energy converted from the vibration energy of the car suspension and the inertia energy of the car to the wheel by virtue of a hydraulic motor mode. The recycled hydraulic energy can select a corresponding mode according to a road condition and can be applied to hydraulic assistance of a car steering device and a disc-type brake hydraulic system.