A method for wirelessly detecting and diagnosing the state parameter of a building or equipment belongs to the technical field of real-time building or equipment parameter test. The method is characterized in that whether corresponding sensors fail or not is detected in real time in a contact or non-contact manner with use of load generation components installed in various ways around or inside the various sensors used by a detected object, so that the system can monitor the dynamic change of a tested state parameter in real time during normal operation of the sensors according to the change threshold range of the tested state parameter, perform diagnosis according to allowed upper and lower thresholds, give an abnormality signal when the change is close or equal to the upper or lower threshold, give an alarm signal when the change reaches an alarm value, and automatically adjust the power supply voltage when the power supply voltage deviates downward from the reference value. The method is applicable to technical fields such as central air conditioning temperature indoor control, machine tool guide track stroke control, seismic detection and equipment destructive resonance, and is more applicable to places which are not easy or suitable for operators to enter.