To provide an improved method for supplying cellulose chips to a continuous high pressure digestion system.

The method and system for supplying the cellulose fiber material to a high pressure treating tank is characterized by comprising a step for pressurizing a low pressure flow of the fiber material with a transport apparatus, a step for discharging a high pressure flow of the fiber material from the transport apparatus to pipes communicating with the treating tank through the fluid, a step for discharging the low pressure flow from the transport apparatus, a step for pressurizing the discharged low pressure flow in the downstream of the transport apparatus, and a step for joining the pressurized flow pressure discharged flow to the discharged high pressure flow.