The invention discloses a cracking pre-warning method and a cracking pre-warning device for a scene bituminous concrete seepage-proofing panel. The device comprises a strain sensor, a loading device, a testing plate and a digital processor, wherein the strain sensor is embedded into the bituminous concrete seepage-proofing panel of an engineering field and is used for collecting the strain data of the panel and transferring the data to the digital processor, and the digital processor sends a command to the loading device to enable the loading device to apply equal strain load to the testing plate; meanwhile, the strain sensor in the loading device is used for transferring a strain value of the applied load to the digital processor, compares the strain value with the intensity of the bituminous concrete seepage-proofing panel, and forecasts whether the seepage-proofing panel has a cracking risk according to a comparison result. The cracking pre-warning method and the cracking pre-warning device for the scene bituminous concrete seepage-proofing panel provided by the invention are capable of forecasting and pre-warning whether the bituminous concrete seepage-proofing panel cracks and effectively avoiding cracking of the bituminous concrete seepage-proofing panel.