The invention relates to a wireless testing method, a testing device and a testing system for deformation of a deep pit. The testing method comprises the following steps: arranging multiple rock soil deformation sensors on the wall of a pit from top to bottom along with the excavation progress of the pit; measuring and outputting the inclination angle information of the wall of the pit at regular intervals or in real time by multiple rock soil deformation sensors; acquiring the deformation information of the pit according to the change information of the inclination angle of each rock soil deformation sensor and performing safety pre-warning on the deformation exceeding the preset condition; and the testing system for deformation of the deep pit comprises a deep pit deformation testing device and a data processing terminal which is wirelessly connected with at least one information acquisition terminal for receiving the inclination angle information of the information acquisition terminal, acquiring the deformation information of the pit and performing safety pre-warning to the condition. According to the testing method and the testing system, the rock soil deformation sensors are adopted to detect and calculate the inclination angle information of the pit wall and acquire the inclination or the horizontal deformation displacement of the pit wall, and an accurate electronic instrument is adopted for measurement and replaces manual measurement, therefore, high-precision deep pit deformation detection can be realized conveniently and rapidly, and real-time monitoring and timely pre-warning can be ensured as required.