Online diagnosis method for reciprocating mechanical failure

The invention provides an online diagnosis method for reciprocating mechanical failure, which includes a parameter setting module, a signal collecting module, a data processing module, a failure judging module, a humorous frequency recording module, a data displaying module and a data keeping module. The parameters set by the parameter setting module are connected into the signal collecting module to measure the signals like torsional vibration, pressure and temperature, etc, of a target to be measured, and judge whether a voltage signal is within the parameter scope in channel setting or not, partially access the torsional vibration signal in the collected signals into the data processing module, implement FFT treatment on data and implement calculation treatment on torsional angles; the signals except the torsional vibration signal directly enter the next flow and the data respectively enters the humorous frequency recording module, the failure judging module and the data displaying module. The online diagn