Abstract: A biomass combustion system for ceramic roller kiln, including a roller kiln including a preheating section, a combustion section and a cooling section; a biomass gasifier with a feed port, a first gas inlet, a second gas inlet and an gas outlet; a fuel manifold; and a pentane gasification device connected to the fuel manifold. The biomass or biomass waste is fed through the feed port. The gas outlet is connected to the fuel manifold through a heat exchanger. The premixer is configured to mix part of the hot air discharged from the cooling section with a mixture of biomass gas and gaseous pentane transported by the fuel manifold to obtain an air-fuel mixture, and distribute the mixture to the combustion section through burners. A biomass combustion process is also provided.