TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The magnetic ZrO2-Fe3O4 is prepared by mixing iron (II) chloride tetrahydrate and iron chloride hexahydrate at a mass ratio of (1: 2 (III).5)-(10:1) to prepare mixed solution and adding to three-mouth flask, putting in constant temperature water bath of 65 degrees C, slowly stirring at the same time of dripping 0.1 mol/L of sodium hydroxide solution until the pH value of the solution is 12, keep stirring at room temperature and aging for a certain time, and then taking out three-opening flask constant temperature water bath and cooling to room temperature, using the magnetic field for separating the magnetic substrate and the upper layer clear solution, then repeatedly washing to neutral for magnetic matrix, storing for further use in the state of suspending; and preparing magnetic matrix suspension in three-necked bottle, stirring and raising temperature to 65 degrees C, taking out zirconium oxychloride octahydrate, adding water to the suspension, adjusting the pH value of the solution by ammonia water to 13, using magnetic field for separating deposit, removing supernatant fluid, washing with de-ionized water until there is no chlorine ion, and then obtaining the material for filtering, drying and baking to obtain the magnetic ZrO2-Fe3O4 catalytic agent containing 50 wt.% ZrO2. The aging time is 10-120 minutes. The drying temperature is 60-120 degrees C and the drying time is 2-24 hours. The roasting temperature is 350-600 degrees C, speed is 0.5-10 degrees C/minute, and heat preservation time is 4 hours. The magnetic Pd-ZrO2-Fe3O4 is prepared by weighing palladium nitrate into de-ionized water, adding ZrO2-Fe3O4 powder, slowly stirring while dripping ammonia water until the pH value reaches 9, then filtering and drying at room temperature for 12 hours, and drying at reducing hydrogen and nitrogen atmosphere to obtain the Pd-ZrO2-Fe3O4 magnetic zirconium-based catalyst containing 0.1-3% Pd. The drying temperature is 80-120 degrees C, and the drying time is 2-12 hours. The reducing temperature is 260-300 degrees C, rate is 0.5-3 degrees C/minute, and heat preservation time is 2-4 hours.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The biomass is lignocellulose biomass. Preferred Method: The pyrolysis reaction is not more than 20 seconds.