To provide a connecting method of precast concrete structure members capable of easily connecting the PCa structure members by greatly improving workability without projecting reinforcement when the PCa structure members are connected and, at the same time, carrying out every structure member by a PCa method.

A sleeve 3a is provided to the PCa structure member 1a, a screw cut connection reinforcement 4 is moveably inserted in the sleeve 3a, and a nut 6 is screwed to the front end of the connection reinforcement 4. The sleeve 3a of the PCa structure member 1a and a sleeve 3b of the PCa structure member 1b are opposingly arranged to each other, and the connection reinforcement 4 is moved upward by rotating the nut 6. When the connection reinforcement 4 is moved inside of the sleeve 3b of the PCa structure member 1b by a predetermined quantity, the sleeves 3a and 3b are filled with grout materials 8a and 8b to fix.