The invention discloses a preparation and refining method for 
citral. The method includes: 1) in an 
atmospheric oxygen-free environment, taking 
alcohol ether as a 
solvent and alkylsulfone as a cosolvent, adjusting the pH value by 
benzoic acid or 
phenylacetic acid, subjecting 
dehydrolinalool to catalytic rearrangement under 
catalysis of a 
molybdenum acetylacetonate catalyst so as to generate 
citral, with the 
dehydrolinalool, the 
solvent and the cosolvent being in a 
mass ratio of 1:(1-4):(0.2-0.8), and with the dosage of the catalyst accounting for 2-8% of that of 
dehydrolinalool, controlling the pH value at 3-5, the reaction time at 3-9h, and 
reaction temperature at 100-125DEG C; 2) subjecting a 
citral-containing reaction liquid to vacuum rectification to remove light components (including the cosolvent and unreacted dehydrolinalool), with a concentrated citral solution (mainly containing citral and the 
solvent) left at the 
tower bottom, and controlling the operation pressure at 0.02-0.08MPa, the 
tower bottom temperature at 40-80DEG C, and the 
reflux ratio at 4-10; and 3) carrying out vacuum rectification on the concentrated citral solution obtained at the 
tower bottom to obtain a high purity citral product, which has a citral purity up to 95.7%, and controlling the operation pressure at 0.008-0.06MPa, the tower bottom temperature at 40-80DEG C and the 
reflux ratio at 4-10. The method provided by the invention has very obvious positive effects, makes use of the good 
solubility of the 
molybdenum catalyst in the 
alcohol ether solvent, not only improves the citral yield, but also realizes recycling of the catalyst dissolved in the solvent. Complex 
processing steps in the prior art are avoided, and the process is simplified.