The invention provides a detecting tool for a field main body structure in an engineering inspection test. A touch control panel is arranged at a main body; a battery and a controller are arranged inside the main body; a first sliding rail, a position finder bracket, a reinforcing steel bar position finder, a mortar strength detector, and an identification device are arranged at the bottom of themain body; and a longitudinal moving device and a lateral moving device are arranged at the bottom of the main body. The mortar strength detector consists of a detector pedestal and a housing; a detection rod and a detection cone are arranged inside the housing; the base of the detection rod is made of a magnet material and is connected with a pressure sensor arranged inside the detector pedestal;and an electromagnet is arranged inside the spring. An ink outlet and an ink spraying device are arranged inside the identification device; an ink outlet column of the ink spraying device moves up and down and thus a cavity structure is connected or disconnected with external space. According to the invention, different data can be detected in field engineering detection for measuring the engineering main body structure at a dangerous or inaccessible place; and automatic marking and data transmission are carried out simultaneously, so that the work efficiency is improved.