Measuring tool for radiotherapy equipment and use method

The invention provides a measurement tool for radiotherapy equipment and a use method, and relates to the technical field of medical instruments, the measurement tool for the radiotherapy equipment comprises a positioning assembly and a measurement assembly, the measurement assembly is detachably arranged on the positioning assembly and extends in the direction away from the positioning assembly, and the measurement assembly is detachably arranged on the positioning assembly. The measuring assembly is provided with a detection cavity in the length direction, an opening of the detection cavity is located at one end of the measuring assembly close to the positioning assembly, and the bottom of the detection cavity is provided with a coordinate identifier. The measuring tool for the radiotherapy equipment provided by the invention can be used for one of calibration of a standard alignment state of a treatment head of the radiotherapy equipment, treatment head alignment error detection or radiation beam axis devi