The invention discloses a suspension device of an electric pallet truck. The suspension device of the electric pallet truck comprises a drive installation board used for installation of a drive unit, the drive installation board is provided with a connection rod mechanism, the connection rod mechanism is movably connected with a truck frame of the electric pallet truck, the drive installation board is provided with a compressed spring, and the top end of the compressed spring is provided with an adjusting mechanism for adjusting the pressing force of the compressed spring. According to the suspension device of the electric pallet truck, the drive installation board operates synchronously and stably under driving of synchronous rotation of the connection rod mechanism; the adjusting mechanism adjusts the compressed spring and enables the compressed spring to have different pressing forces, the connection rod mechanism is matched with the reactive force of the compressed spring to effectively compensate for wheel pressure of a drive wheel, the phenomena such as slipping and hard steering caused by changes of wheel pressure of the drive wheel are avoided, impact to the truck by the road surface is also reduced greatly, the suspension function is achieved, and the driving comfort level of the whole truck is improved; meanwhile, the adjusting mechanism has the advantages of being simple in structure and convenient to operate, adjustment is visual and rapid, observation is convenient, and operation is convenient.