The invention relates to a single-bed two-stage furfural, paper pulp and lignin polygeneration system and method capable of continuous operation. The method comprises the steps that raw materials, vapor, a catalyst and a solvent are mixed and boiled in a pressurized reaction kettle, through improvement on the structure of a reactor and parameter optimization, furfural, paper pulp and lignin are prepared at the same time, and continuous operation is achieved; duo to use of a cyclone separator in the pressurized reaction kettle, internal circulation of a mixing boiling section and a stripping section, a plurality of vapor distributors and a plurality of system circulations, the mixing effect of the reaction kettle is improved, the heat and mass transfer rate and the reaction rate are improved, material entrainment at a gas outlet of the stripping section is reduced, and the furfural yield and the technical and economical efficiencies of the system are improved; through sufficient mixingof gas, liquid and solid in the reaction kettle and quick separation of the gas from the solid, improvement of the yield of the paper pulp and improvement of the yield of the lignin are facilitated, and accordingly, optimized combination of the technical and economical efficiencies of the system is achieved.