Thread adjusting clamp and screw installation method

The invention discloses a thread adjusting clamp. The thread adjusting clamp comprises a screw rod (2) and a limiting rod (4) and is characterized in that an internal thread section A (5), an internal thread section B (6) and a through hole (7) are arranged in the limiting rod (4) in sequence, the internal thread section A (5) is matched with an external thread of the screw rod (2), and the diameter of the internal thread section B (6) is equal to the size of a screw needing to be installed; the sum of the length of the internal thread section B (6) and the length of the through hole (7) is equal to the length of an exposed part of the screw needing to be installed; the diameter of the internal thread section A (5) and the diameter of the through hole (7) are larger than the diameter of the internal thread section B (6). According to a screw installation method to which the thread adjusting clamp is applied, the screw can be installed in place at a time, the size and length of the exposed part of the screw are guaranteed, adjustment is not needed, use is convenient, short time is consumed, and the percent of pass is high.