The invention discloses a pressure feed type high-pressure dense-phase pneumatic conveying device and a pneumatic conveying method. Pressure feed type high-pressure dense-phase pneumatic conveying is adopted for providing a device and a method for supplying an ultra-concentrated-phase and high-stable-mass-flow-rate powder material; the structures of a conveying system and a material sending tank are greatly simplified; the shortcomings that a fluidization tank is complicated in form and structure, control requirements of fluidization wind in the tank are relatively high, a conveying tube is unfavorable to fluidization and overall flowing of powder in the tank and the like are avoided; investment is saved; meanwhile, the conveying device needs no power running member, so the safety of the high-pressure conveying device is guaranteed better. According to the conveying device disclosed by the invention, the gas-solid flow velocity is small; the gas-solid impact wear is greatly reduced; the wear resistance of the device is greatly improved; the service life of the device is greatly prolonged; the conveying device is stable, reliable and relatively good in regulation function, has the effect of avoiding the influences caused by unstable conveying to subsequent processes and especially has a more remarkable effect on a technique which requires high stability of subsequent processes of a pneumatic conveying terminal and ultrahigh concentration of coal dust.