Disclosed is a process for the preparation of 2,3,3,3-tetrafluoropropene, comprising the following two reaction steps: a. a compound having the formula CF3-xClxCF2-yClyCH2Cl undergoes gas-phase fluorination with hydrogen fluoride through n serially-connected reaction vessels in the presence of a compound catalyst, producing 2,3-dichloro-1,1,1,2-tetrafluoropropane, 1,2,3-trichloro-1,1,2-trifluoropropane, and 1,3-dichloro-1,1,2,2-tetrafluoropropane; in said formula, x=1, 2, 3, y=1, 2, and 3≦x+y≦5; b. the 2,3-dichloro-1,1,1,2-tetrafluoropropane, 1,2,3-trichloro-1,1,2-trifluoropropane, and 1,3-dichloro-1,1,2,2-tetrafluoropropane undergo gas-phase dehalogenation with hydrogen in the presence of a dehalogenation catalyst, producing 2,3,3,3-tetrafluoropropene and 3-chloro-2,3,3-trifluoropropene, then separation and refining are performed, producing 2,3,3,3-tetrafluoropropene. The present invention is primarily used to produce 2,3,3,3-tetrafluoropropene.