The invention relates to a detection method and a detection device for impact energy of a hydraulic breaking hammer. The detection method comprises the following steps: firstly, a pressure sensor detects the impact force of a drill rod of the breaking hammer and converts into voltage signals. Secondly, a data collection card collects the voltage signals. Thirdly, a computer reads data collected by the data collection card and processes the data. And lastly, the computer outputs the processing result through an output module. The detection device comprises the pressure sensor, the data collection card, the computer and the output module, wherein the pressure sensor, the data collection card, the computer and the output module are connected in sequence, and the pressure sensor is fixed on an action level plane of the drill rod of the breaking hammer through a senor fixing part. Compared with the prior art, the detection method and the detection device for impact energy of a hydraulic breaking hammer have the advantages of being simple in method, convenient to operate, accurate in detection result, and the like.