The invention provides an inertial container device with a continuously-adjustable inertia coefficient. The inertial container device comprises a driving wheel, a driven wheel, a gear, a rack/flywheel/hydraulic pump, a driving wheel hydraulic control cylinder and a driven wheel hydraulic control cylinder, wherein a V-shaped groove is formed between the movable part and the fixed part of the driving wheel; the gear is arranged on a driving shaft, and is meshed with the rack; a V-shaped groove is formed between the movable part and the fixed part of the driven wheel; the flywheel is arranged on a driven shaft; the driven wheel is driven by an elastic metal belt arranged in the two V-shaped grooves; the movable parts of the driving wheel and the driven wheel are driven by the driving wheel hydraulic control cylinder and the driven wheel hydraulic control cylinder which are connected with a hydraulic pump respectively. The engagement radius of the metal belt is adjusted through axial movement of the movable part of the driving wheel and the movable part of the driven wheel, so that the transmission ratio between the driving wheel and the driven wheel is adjusted, and continuous adjustment of the inertia coefficient is realized.