Connecting device and connecting method for steel structure and steel bar

The invention discloses a connecting device and method for a steel structure and a steel bar. The connecting device comprises a base (3), a mounting plate (4), a rotary clamping assembly, a buffering assembly and a positioning assembly. The base is mounted on a steel structure (1), and the mounting plate is mounted on the base through the buffer assembly; mounting holes (5) are formed in the mounting plate, grooves (16) are formed in the base, and reinforcing steel bars (2) penetrate through the mounting plate through the mounting holes and are inserted into the base through the grooves; the positioning assembly is embedded in the base, one end of the positioning assembly is inserted into the open groove and abuts against the steel bar, and the other end of the positioning assembly penetrates through the base downwards. And the rotating clamping assembly is embedded in the mounting plate and comprises a rotating mechanism and clamping mechanisms, the multiple clamping mechanisms are connected with the rotatin