To provide a method of manufacturing a precast concrete column member, for easily and quickly positioning column main reinforcements projected to the outside of a form, in a manner avoiding displacement of the same, to thereby advantageously achieve cost reduction.

According to the method, the plurality of column main reinforcements T projected from an end face 1202 of the form 12 are inserted into respective reinforcement insertion holes 32 formed in a first positioning plate 20 which is then arranged so as to be opposed to the end face 1202. Then a second positioning plate 22 is arranged so as to face the first positioning plate 20 in a manner locating an end lower surface of each column main reinforcement T on a mounting surface 42 thereof and in a manner bringing an end face of each column main reinforcement T close to an abutting surface 44. Next the first and second positioning plates 20, 22 are set at predetermined locations, and a V-shaped upper edge 32B of each reinforcement insertion hole 32 is pressed to an upper surface of the column main reinforcement T. Further each abutting surface 44 is abutted on the end face of the column main reinforcement T, and each mounting surface 42 is abutted on the end lower surface of the column main reinforcement T.